Fixed: "No Devices Attached" due to ArgumentNullException in System.Version..ctor

BrendanZagaeskiBrendanZagaeski USForum Administrator, Xamarin Team Xamurai
edited November 2014 in Visual Studio

Update October 31, 2014: Fix published to the stable channel

The version of Xamarin.iOS (8.4.0.16) that includes the fix has now been published to the stable channel.

Update October 24, 2014: Candidate hotfix build

http://xvs.xamarin.com/monotouch-8.4.0.16.pkg

Here is a Xamarin.iOS installer build that includes a candidate fix for the Mac build host. This has solved the problem for at least 6 different users. Please keep in mind that this build has only been lightly tested, and only for this particular problem. As a result, there is at least a small chance it might break some other functionality that would normally be caught before a hotfix release. Barring any unexpected test failures, it will be published to the stable channel during the next Xamarin.iOS stable update.

Be sure to quit and re-open the Xamarin.iOS Build Host app after installing this package.

Note that there are other a couple other possible causes of the "No Devices Attached" message (if the mtbserver.log file does not contain the "Argument cannot be null" error):

  • A Xamarin.iOS app project is not currently set as the "Startup Project".
  • The active platform for the Xamarin.iOS app project is not currently set to "iPhone" or "iPhoneSimulator" under "Build -> Configuration Manager".

Update October 16, 2014

The hotfix releases that were just published to the stable channel include some changes for how the device listing works. They might improve the success rate of the device listing process.

  • Windows: Xamarin 3.7.226
  • Mac build host: Xamarin.iOS 8.2.0.207

Follow-up: the hotfix does not resolve the issue, but disabling Wi-Fi sync via iTunes does help

I can confirm Tim.Miller's excellent observation that enabling Wi-Fi sync for a device within Wi-Fi range is sufficient to cause this problem. I can reproduce the issue very reliably on the latest stable builds using this approach.

For anyone seeing this problem, be sure to try disabling this setting in iTunes for all nearby devices (or switching off Wi-Fi altogether on all of the devices).

  1. Un-check the "Sync with this iPhone over Wi-Fi" option.
    iTunes, Options -> Sync with this iPhone over Wi-Fi

  2. Click "Apply".

  3. Quit iTunes.

This might not resolve the problem in all cases, but it definitely solves a few of the cases. I've added this information to the bug report to help the developers investigate the problem. I think with this new reliable way to reproduce the issue, they will be able to make steady progress.


Starting with Xamarin 3.6, Xamarin.iOS 8.0, and Xcode 6, several users have been hitting a problem where iOS devices will not appear in the device list in Visual Studio. Instead the device list will always say "No Devices Attached".

Based on the corresponding exception message and stack trace, it seems likely that the in-progress fixes for the "(500) Internal Server Error" will help with this problem too. Those fixes are related to Mtb.Server.DeviceListener and Mtb.Server.Commands.ListDevices.GetDevices(). Candidate hotfix builds for that problem will hopefully be available soon.

In the mean time, here are a couple questions for any users who might be seeing this:

  • Are you by chance using a Parallels VM to run Windows? If the problem is more likely to happen in Parallels, that might help the developers reproduce and debug the problem.

  • Does switching to Xcode 5 (without downgrading Xamarin) avoid the problem?

Possible temporary workarounds

  • If the problem depends on Xcode 6, then the same workarounds for the "(500) Internal Server Error" might help with this problem too. In particular, switching back to Xcode 5 might stop the problem. See http://forums.xamarin.com/discussion/25504/ios-designer-500-internal-server-error-avoid-by-using-xcode-5 for more details.

    One user reported that downgrading to Xamarin 3.5.58, Xamarin.iOS 7.4.0.108, and Xcode 5 did successfully stop the problem, but there's a decent chance that downgrading just Xcode will help.

  • One user reported that reinstalling the current Xamarin version using the individual .msi installer package helped.

  • Clearing the log files and caches and re-pairing has helped temporarily in some cases too:

    1. Delete the following folders on the Mac build host:
      ~/Library/Logs/Xamarin/MonoTouchVS
      ~/Library/Caches/Xamarin/mtbs

    2. Delete the following folder on the Windows machine:
      %LOCALAPPDATA%\Xamarin\Log

    3. Click the "Unpair" button on the Xamarin.iOS Build Host app, and then re-pair again with Visual Studio.

The exception message and stack trace

Here's the full error message from the mtbserver.log file:

// Exception: Exception type: System.ArgumentNullException
// Argument cannot be null.
// Parameter name: version
//   at System.Version..ctor (System.String version) [0x00000] in <filename unknown>:0 
//   at Mtb.Server.DeviceListener.<GetDevices>m__1 (Xamarin.MacDev.IPhoneDevice d) [0x00000] in <filename unknown>:0 
//   at System.Linq.Enumerable+<CreateSelectIterator>c__Iterator10`2[Xamarin.MacDev.IPhoneDevice,Mtb.Server.Device].MoveNext () [0x00000] in <filename unknown>:0 
//   at System.Collections.Generic.List`1[Mtb.Server.Device].AddEnumerable (IEnumerable`1 enumerable) [0x00000] in <filename unknown>:0 
//   at System.Collections.Generic.List`1[Mtb.Server.Device]..ctor (IEnumerable`1 collection) [0x00000] in <filename unknown>:0 
//   at System.Linq.Enumerable.ToList[Device] (IEnumerable`1 source) [0x00000] in <filename unknown>:0 
//   at Mtb.Server.DeviceListener.GetDevices () [0x00000] in <filename unknown>:0 
//   at Mtb.Server.Commands.ListDevices.GetDevices () [0x00000] in <filename unknown>:0 
//   at Mtb.Server.Commands.ListDevices.HandleRequest (ILoggingHelper logger, System.Object commandRequestState) [0x00000] in <filename unknown>:0 
//   at Mtb.Server.BaseCommand.OnRequest (System.Net.HttpListenerContext context, System.Object commandRequestState) [0x00000] in <filename unknown>:0 
//   at Mtb.Server.Listener.OnRequest (System.Object state) [0x00000] in <filename unknown>:0 // Argument cannot be null.

For some reason the call to Mtb.Server.DeviceListener.<GetDevices>m__1 (Xamarin.MacDev.IPhoneDevice d) is attempting to create a new System.Version object with a null input:

new System.Version(null)

Presumably this means that an earlier method call is failing silently and returning null instead of a valid version string like "7.1.2". That kind of failure sounds like it could be the result of an Objective-C method call or a failed as conversion. Just to make one guess, the explanation might be that Xcode 6 sometimes return null when the build server queries it for the iOS versions of the attached simulators and devices. This could even be an intentional behavior of Xcode 6. If that is the case, then the Xamarin build server will need to be adjusted accordingly.

The error is intermittent

On at least a few users' machines, this problem is currently appearing and disappearing "unpredictably."

For example, in one case, the Mtb.Server.DeviceListener.GetDevices() command would fail repeatedly with the ArgumentNullException. But then, after both computers had been left untouched for a few minutes, the problem would eventually stop, and the device list in Visual Studio would refresh correctly. The mtbserver process did not crash or restart during this time: the mtbserver process ID stayed the same, and no new crash logs appeared in "Console.app -> User Diagnostic Reports". This system had Visual Studio installed in a Parallels VM on the Mac build host (OS X 10.9.5).

In another case, each time the user installed a new Xamarin update from the updater service, the problem would stop temporarily (for maybe a day or two).


EDIT October 16: Mention the new hotfix build. It includes some changes in the device listing code that might help with the problem.
EDIT October 17: The hotfix from October 16 did not solve the problem, but disabling Wi-Fi sync via iTunes can definitely help (at least in some cases).
EDIT October 24: Candidate hotfix build.
EDIT October 31: Fix published to the stable channel

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Posts

  • AmmonManningAmmonManning USMember ✭✭

    Same issue here. I'm running Visual Studio from within VMWare Fusion on an iMac. It worked yesterday after I removed and reinstalled all the Xamarin programs in Windows, but now I am getting the same null error and no devices attached message. I tried rebooting everything, deleting all the log files as mentioned above, but nothing fixed it. I'm downloading Xcode 5.1.1 now to see if that fixes the issue, but the download is really slow for some reason...

  • Tim.MillerTim.Miller USMember

    I am seeing this bug "intermittently" but usually it doesn't report any devices. I am not using any kind of VM on either windows or mac, and I am trying to deploy to an ios 8 device, which I think means I can't use Xcode 5. It seems to be fairly consistently working (reporting devices) after closing and restarting the build host (and sometimes re-pairing) when I do not have the physical ipad attached. Attaching the ipad causes it to get the null exception again.

  • AmmonManningAmmonManning USMember ✭✭

    Downloaded and installed Xcode 5.1.1. Rebooted the iMac and unpaired/repaired Visual Studio. Same error:

    [09-Oct-2014 13:56:07] Error: Command [ListDevices: CommmandUrl=ListDevices] failed.
    [09-Oct-2014 13:56:07] Exception: Exception type: System.ArgumentNullException
    Argument cannot be null.

  • Tim.MillerTim.Miller USMember

    In fact, simply turning my ipad on, not even plugged in to anything, causes the build host to get the null exception/no devices problem again, and the problem goes away as soon as the ipad is turned off. This ipad is set up to wirelessly sync with the mac Xamarin is on; if I turn wifi syncing off, turn off the ipad, and turn it on, it no longer causes the null exception. Plugging it in to the mac at that point (with wifi sync off) no longer causes the null problem (I'm now seeing a list of all devices, including the ipad, even though the ipad is plugged in). I guess I'll see if anything else causes this problem now I have wifi sync off.

  • GregStevensonGregStevenson GBMember ✭✭
    edited October 2014

    I'm experiencing this too - I emailed support earlier before I came across this thread.

    @BrendanZagaeski‌:
    Are you by chance using a Parallels VM to run Windows? If the problem is more likely to happen in Parallels, that might help the developers reproduce and debug the problem.

    Yes, I am. Mac OS 10.10 Yosemite running the latest GM seed, with Parallels Desktop 10.0.0 (27675) hosting a Windows 8 VM. I can also confirm that it's intermittent (although fails a lot more than it succeeds). I'm not able to downgrade to Xcode 5 because we need to verify our app runs on iPhone 6/6+.

  • FabianWilliamsFabianWilliams USUniversity, Developer Group Leader ✭✭

    Im having the same issue as well. I just updated Xamarin on both PC and Mac to latest update and even got prompted to update IOS SDK on Windows box. Issue is unresolved for me. Im on VS 2013 Premium, Parallels 10, Xcode 6.01 -- mine is not intermittent, it is persistent. My experience is that my project works until i plug in my phone. Any update @XamarinHQ

  • AmmonManningAmmonManning USMember ✭✭

    Any update? I'm currently using the downgraded versions with Xcode 5.1.1. However, I only have an iPhone 6 device, so I can't debug anything until this gets resolved...

  • DomiBDomiB BEBeta, University ✭✭

    Hmm, I was having this problem as well. (with Visual studio 2013 in a Parallels VM). Stopping and starting XCode made it go away (for now)?

  • BrendanZagaeskiBrendanZagaeski USForum Administrator, Xamarin Team Xamurai

    Hi all, the hotfix releases that were just published include some changes to how the device listing is run. These changes might improve the reliability of the device listing, at least in some cases.

    I've updated the first post in the thread accordingly.

    We'd be interested in any changes in the "No Devices Attached" behavior observed with these new builds. Thanks!

  • CamiloFierroCamiloFierro COMember, University

    I'm using Yosemite under a Parallels VM with the latest Xamarin updates and the device list constantly alternates between 'No devices Attached' and the list of devices. It looks like the devices list drops, then the build host makes several attempts to get it. After a few failed attempts, the list is refreshed correctly; but after a few minutes the same thing happens.

  • BrendanZagaeskiBrendanZagaeski USForum Administrator, Xamarin Team Xamurai

    @CamiloFierro‌, two questions:

    1. Just to confirm, I assume you have already updated to the latest hotfix versions:

      • Windows: Xamarin 3.7.226
      • Mac build host: Xamarin.iOS 8.2.0.207
    2. Do you see the same "ArgumentNullException" and stack trace from the first post in your mtbserver.log file? If not, then we can start up a new thread + bug report for the issue you're seeing.

  • CamiloFierroCamiloFierro COMember, University
    edited October 2014

    @BrendanZagaeski‌ Yes, I'm using the latest hotfix versions.

    Here's my stack trace (which is the same one as the one you posted):

    // Error: Command [ListDevices: CommmandUrl=ListDevices] failed.
    // Exception: Exception type: System.ArgumentNullException
    // Argument cannot be null.
    // Parameter name: version
    //   at System.Version..ctor (System.String version) [0x00000] in <filename unknown>:0 
    //   at Mtb.Server.DeviceListener.<GetDevices>m__1 (Xamarin.MacDev.IPhoneDevice d) [0x00000] in <filename unknown>:0 
    //   at System.Linq.Enumerable+<CreateSelectIterator>c__Iterator10`2[Xamarin.MacDev.IPhoneDevice,Mtb.Server.Device].MoveNext () [0x00000] in <filename unknown>:0 
    //   at System.Collections.Generic.List`1[Mtb.Server.Device].AddEnumerable (IEnumerable`1 enumerable) [0x00000] in <filename unknown>:0 
    //   at System.Collections.Generic.List`1[Mtb.Server.Device]..ctor (IEnumerable`1 collection) [0x00000] in <filename unknown>:0 
    //   at System.Linq.Enumerable.ToList[Device] (IEnumerable`1 source) [0x00000] in <filename unknown>:0 
    //   at Mtb.Server.DeviceListener.GetDevices () [0x00000] in <filename unknown>:0 
    //   at Mtb.Server.Commands.ListDevices.GetDevices () [0x00000] in <filename unknown>:0 
    //   at Mtb.Server.Commands.ListDevices.HandleRequest (ILoggingHelper logger, System.Object commandRequestState) [0x00000] in <filename unknown>:0 
    //   at Mtb.Server.BaseCommand.OnRequest (System.Net.HttpListenerContext context, System.Object commandRequestState) [0x00000] in <filename unknown>:0 
    //   at Mtb.Server.Listener.OnRequest (System.Object state) [0x00000] in <filename unknown>:0 
    
  • JGoldbergerJGoldberger USMember, Forum Administrator, Xamarin Team, University Xamurai

    Plugging in a physical device seems to have resolved the issue in my setup. (Parallels VM running 8.1 and Vis Studio 2013 Update 3). None of the other workarounds noted worked on my end, not even the hot fix. After applying the hot fix, I tried doing an SDK sync to the Mac, which presumably undid the hot fix update for iOS (XI v 8.2.0.0 in Visual Studio after the sync), but that did not help. Plugging in the device was the only thing that let the device list populate consistently, even after unplugging the physical device.

  • BrendanZagaeskiBrendanZagaeski USForum Administrator, Xamarin Team Xamurai

    Update: I can confirm Tim.Miller's excellent observation that enabling Wi-Fi sync for a device within Wi-Fi range is sufficient to cause this problem. I can reproduce the issue very reliably on the latest stable builds using this approach.

    For anyone seeing this problem, be sure to try disabling this setting in iTunes for all nearby devices (or switching off Wi-Fi altogether on all of the devices).

    1. Un-check the "Sync with this iPhone over Wi-Fi" option.
      iTunes, Options -> Sync with this iPhone over Wi-Fi

    2. Click "Apply".

    3. Quit iTunes.

    This might not resolve the problem in all cases, but it definitely solves a few of the cases. I've added this information to the bug report to help the developers investigate the problem. I think with this new reliable way to reproduce the issue, they will be able to make steady progress.

  • DanVanderboomDanVanderboom USUniversity ✭✭

    I was having the same problem. I tried several of the solutions suggested here (reinstall Xamarin tools, disable iTunes WiFi sync) but the problem persisted.

    Finally I rebooted my wireless router, and when it came back online, this problem of not listing my connected iOS device through the iOS Build Host went away.

    I thought it might be a fluke at first, so I've been waiting to say anything, but it's been a few hours and is still working just fine for me now.

    If you reboot your wireless router and for some reason you also get it working again, I'd be curious to hear.

  • CamiloFierroCamiloFierro COMember, University

    @BrendanZagaeski‌
    Happy to report that after enabling (was disabled) and disabling iTunes Wi-Fi Sync on one of my devices, it works flawlessly. How weird is that?

  • I went to Yosemite yesterday and have been having this problem since then. I have tried many of the solutions mentioned above and still have very intermittent build host functionality.

  • Still no luck with any of the workarounds! VS is totally useless for me at the moment...

  • TravisHeseman.3879TravisHeseman.3879 USUniversity
    edited October 2014

    I too am having this issue. Had it most of the day yesterday so I upgraded to Yosemite and then XCode to see if that would help. No go. I uninstalled Xamarin from the Mac following all the Terminal instructions and reinstalled. No go. I uninstalled and reinstalled on Windows in Parallels (the host is a MBP and that's where the build host is). No go. See below stack trace from mtbserver.log

    [22-Oct-2014 15:47:49] Exception: Exception type: System.ArgumentNullException
    Argument cannot be null.
    Parameter name: version
      at System.Version..ctor (System.String version) [0x00000] in <filename unknown>:0 
      at Mtb.Server.DeviceListener.<GetDevices>m__1 (Xamarin.MacDev.IPhoneDevice d) [0x00000] in <filename unknown>:0 
      at System.Linq.Enumerable+<CreateSelectIterator>c__Iterator10`2[Xamarin.MacDev.IPhoneDevice,Mtb.Server.Device].MoveNext () [0x00000] in <filename unknown>:0 
      at System.Collections.Generic.List`1[Mtb.Server.Device].AddEnumerable (IEnumerable`1 enumerable) [0x00000] in <filename unknown>:0 
      at System.Collections.Generic.List`1[Mtb.Server.Device]..ctor (IEnumerable`1 collection) [0x00000] in <filename unknown>:0 
      at System.Linq.Enumerable.ToList[Device] (IEnumerable`1 source) [0x00000] in <filename unknown>:0 
      at Mtb.Server.DeviceListener.GetDevices () [0x00000] in <filename unknown>:0 
      at Mtb.Server.Commands.ListDevices.GetDevices () [0x00000] in <filename unknown>:0 
      at Mtb.Server.Commands.ListDevices.HandleRequest (ILoggingHelper logger, System.Object commandRequestState) [0x00000] in <filename unknown>:0 
      at Mtb.Server.BaseCommand.OnRequest (System.Net.HttpListenerContext context, System.Object commandRequestState) [0x00000] in <filename unknown>:0 
      at Mtb.Server.Listener.OnRequest (System.Object state) [0x00000] in <filename unknown>:0 
    
  • BrendanZagaeskiBrendanZagaeski USForum Administrator, Xamarin Team Xamurai

    The Xamarin VS team has a candidate fix for the issue. Work is under way to get an updated build out for wider testing. I'll update this thread as soon as I have more information. As I understand it, the issue is approximately that Xcode is "sometimes" (the full list of possible causes isn't clear) adding additional "devices" to the device list that don't correspond to actual physical devices or simulators, and those "devices" have undefined iOS versions.

  • Yesterday I did some testing again. I started XCode, started a new project, run the small project. Then started Visual Studio, and ... the simulators were there! But later that day, without closing any of the apps, they disappeared again...

  • FergalFergal GBMember
    edited October 2014

    I updated to the latest version (details below) this morning, but still getting the same issue. The device list will be populated, and without restarting any of the apps, they will disappear. There doesn't seem to be an obvious set of steps that will bring it back either, I just end up screwing around with closing/opening apps or restarting until they reappear.

    This occurs on both the Sim list, and the list of physical devices.

    I'm also running this from a physical windows machine, to the mac.

    [Visual Studio]
    Xamarin 3.7.230.0;
    Xamarin.Android 4.18.0.39;
    Xamarin.iOS 8.4.0.0;
    Xamarin Studio 5.5.2 (build 0)

    [Mac]
    Xamarin Studio 5.5.2 (build 3);
    Xamarin.iOS 8.4.0.15;
    Xamarin.Android 4.18.0

  • I updated about an hour ago and things appear to be working again.

    Build Host is 3.7.0.324
    Xamarin.iOS is 8.4.0.15

  • IanLIanL USMember

    Definitely not working with Build Host 3.7.0.324, Xamarin.iOS is 8.4.0.15. I ensured WiFi Sync is off. Visual Studio is completely unusable.

  • PortiaBassPortiaBass USMember, University

    Visual Studio "No Devices Found" after successfully pairing with Xamarin iOS Build Host.

    This is a show stopper problem for me. With this problem I cannot do what Xamarin claims is its main feature for c# developers: iOS development in Visual Studio. I have been struggling with the problem for 2 weeks. I have wasted a great deal of time. For me, problem has not been intermittent as I have never gotten it to work with the various updates. Have tried all suggestions on forums; however, I have not tried non "stable" versions. I did try reverting to XCODE 5 with no joy.

    The information on my Visual Studio 2013 and Mac Xamarin Studio is below.

    Visual Studio:
    Microsoft Visual Studio Professional 2013
    Version 12.0.30723.00 Update 3
    Microsoft .NET Framework
    Version 4.5.51641

    Installed Version: Professional

    Visual C# 2013 06177-004-0444002-02630
    Microsoft Visual C# 2013
    Xamarin 3.7.230.0 (e78d10d6993f95fc3ebe791aeb4aacff165bf8bb)
    Visual Studio extension to enable development for Xamarin.iOS and Xamarin.Android.

    Xamarin.Android 4.18.0.39 (0ef616ae42005ece52f6df7aa1e093ceb11998f8)
    Visual Studio plugin to enable development for Xamarin.Android.

    Xamarin.iOS 8.4.0.0 (209abebbd8f1a292d042420edb45fa5fbd3f017b)
    Visual Studio extension to enable development for Xamarin.iOS.

    Mac:
    === Xamarin Studio ===

    Version 5.5.2 (build 3)
    Installation UUID: 77d241a8-775f-46bd-a2d9-4cb847f41e54
    Runtime:
    Mono 3.10.0 ((detached/e204655)
    GTK+ 2.24.23 (Raleigh theme)

                Package version: 310000023
    

    === Apple Developer Tools ===

    Xcode 6.1 (6604)
    Build 6A1052d

    === Xamarin.iOS ===

    Version: 8.4.0.15 (Business Edition)
    Hash: 08968c4
    Branch:
    Build date: 2014-10-20 21:48:06-0400

    === Xamarin.Mac ===

    Version:

    === Build Information ===

    Release ID: 505020003
    Git revision: 6d4c806e383ba366b15fbccca9ddc1ba94f8d5ad
    Build date: 2014-10-15 15:00:36-04
    Xamarin addins: 069ddd29bb70a42238142eee9bac21a5e4b2f9f9

    === Operating System ===

    Mac OS X 10.9.5
    Darwin Portias-MacBook-Pro.local 13.4.0 Darwin Kernel Version 13.4.0
    Sun Aug 17 19:50:11 PDT 2014
    root:xnu-2422.115.4~1/RELEASE_X86_64 x86_64

  • PortiaBassPortiaBass USMember, University

    Correction: "No Devices Attached" is information shown where iOS devices should be.

  • PortiaBassPortiaBass USMember, University

    Good news. Support helped me find my problem with an interactive session.
    I have been getting the "No devices attached" situation. However, the iOS Build Host log did not show "ArgumentNullException."
    My problem was because in Visual Studio Configuration Manager (under Solutions Configuration menu) showed "x86" when it should have been "iPhone Simulator." I had been using the Store template, which apparently sets this information. It is possible that I accidently changed it or the problem may be in some templates for shared code apps.

  • BrendanZagaeskiBrendanZagaeski USForum Administrator, Xamarin Team Xamurai

    http://xvs.xamarin.com/monotouch-8.4.0.16.pkg

    Here is a Xamarin.iOS installer build that includes a candidate fix for the Mac build host. This has solved the problem for at least 6 different users. Please keep in mind that this build has only been lightly tested, and only for this particular problem. As a result, there is at least a small chance it might break some other functionality that would normally be caught before a hotfix release. Barring any unexpected test failures, it will be published to the stable channel during the next Xamarin.iOS stable update.

    Be sure to quit and re-open the Xamarin.iOS Build Host app after installing this package.

    Note that there are other a couple other possible causes of the "No Devices Attached" message (if the mtbserver.log file does not contain the "Argument cannot be null" error):

    • A Xamarin.iOS app project is not currently set as the "Startup Project".
    • The active platform for the Xamarin.iOS app project is not currently set to "iPhone" or "iPhoneSimulator" under "Build -> Configuration Manager" (as Portia mentioned).
  • AmmonManningAmmonManning USMember ✭✭

    That fix is currently working for me! But only time will tell if it keeps working....

  • rogiheerogihee NLMember ✭✭✭

    Hi Brendan, the fix is working for me too! Even without starting the build host app, the devices immediately showed up in VS2013.

  • .15 version wasn't good, updated to .16 and up now, it's ok, no issues.

  • After update issue didn't occur since today. Again it occurs randomly.
    Xamarin.iOS 8.4.0.15
    Build Host 3.7.0.234
    It's the same old error:
    Argument cannot be null.
    Parameter name: version
    at System.Version..ctor (System.String version) [0x00000] in :0
    at Mtb.Server.DeviceListener.m__1 (Xamarin.MacDev.IPhoneDevice d) [0x00000] in :0
    at System.Linq.Enumerable+c__Iterator102[Xamarin.MacDev.IPhoneDevice,Mtb.Server.Device].MoveNext () [0x00000] in <filename unknown>:0 at System.Collections.Generic.List1[Mtb.Server.Device].AddEnumerable (IEnumerable1 enumerable) [0x00000] in <filename unknown>:0 at System.Collections.Generic.List1[Mtb.Server.Device]..ctor (IEnumerable1 collection) [0x00000] in <filename unknown>:0 at System.Linq.Enumerable.ToList[Device] (IEnumerable1 source) [0x00000] in :0
    at Mtb.Server.DeviceListener.GetDevices () [0x00000] in :0
    at Mtb.Server.Commands.ListDevices.GetDevices () [0x00000] in :0
    at Mtb.Server.Commands.ListDevices.HandleRequest (ILoggingHelper logger, System.Object commandRequestState) [0x00000] in :0
    at Mtb.Server.BaseCommand.OnRequest (System.Net.HttpListenerContext context, System.Object commandRequestState) [0x00000] in :0
    at Mtb.Server.Listener.OnRequest (System.Object state) [0x00000] in :0

    What bugs me the most that this is incredibly random: as I was writing this it started working correctly again.

  • BrendanZagaeskiBrendanZagaeski USForum Administrator, Xamarin Team Xamurai

    @SteponasBreidokas‌, when you get a chance, you can try the Xamarin.iOS 8.4.0.16 installer for Mac that I linked in my earlier comments:
    http://xvs.xamarin.com/monotouch-8.4.0.16.pkg

    This installer will also be published to the stable channel in the near future.

  • BrendanZagaeskiBrendanZagaeski USForum Administrator, Xamarin Team Xamurai

    The version of Xamarin.iOS (8.4.0.16) that includes the fix has now been published to the stable channel.

  • JonCortezJonCortez USUniversity ✭✭

    @BrendanZagaeski‌ - I installed 8.4.0.16 from the link you provided last week. Do I still need to update my install from the stable channel?

  • BrendanZagaeskiBrendanZagaeski USForum Administrator, Xamarin Team Xamurai

    @JonCortez‌, you should be all set. The installer that was published to the stable channel is the same one (same MD5 checksum) from last week's download link.

  • BillWarnerBillWarner USMember

    Than you Portia! BTW how did you get an interactive session w/support? I sent them an email and got no reply. At all.

  • hasanirmakhasanirmak CHMember ✭✭

    hi, this is what i get from windows

    http://pastebin.com/WCpmUgQH

    as you see i dont have any problem with emulator. my problems are with designers..

    I installed the latest versions and followed the link

    http://forums.xamarin.com/discussion/25636/fixed-no-devices-attached-due-to-argumentnullexception-in-system-version-ctor/p1

    but still i have the same problem.. Well For Mac OS xamarin studio

    and details here
    http://pastebin.com/NqDQUAxP

    as you see, details are completely different..

    So I do not know what is the problem. We have also another mac machine and it is not problem there.

    Here are my versions

    visual studio 2013
    xamarin studio on mac 5.5.3 (build 6)
    xcode 5.1.1 (5B1008) (I've never updated XCode)
    xamarin.ios windows 3.7.248
    xamarin.ios osx 8.4

    So what is the next? I have to do the project as soon as possible..

  • BrendanZagaeskiBrendanZagaeski USForum Administrator, Xamarin Team Xamurai

    @hasanirmak‌, that is indeed a different problem. The first step will be to get the designer to work in Xamarin Studio on OS X. You can either create a new forum thread for this issue, or since it looks like you have a business license, you can email Xamarin support via [email protected] (or even better, use one of the email addresses listed on https://store.xamarin.com/account/) for one-on-one troubleshooting help.

This discussion has been closed.