I got my binaries rejected when I tried to update my app on iOS store.
I'm using Xamarin.Forms 18.104.22.16805.
As much as possible I don't want to upgrade my Xamarin Forms package because this is going to be a lot of work fixing stuff and compatibility issues for such a minor update of my app.
I tried using both Xamarin Studio 6.3 and Visual Studio 7.0.1 for Mac using Mono 4.8 (It won't build on Mono 5.0+ because of XamlC error on pre-Xamarin.Forms 2.3 versions)
By the way, this build works fine when signed by an AdHoc certificate and tested on our devices.
Here is the crash log from apple.
Incident Identifier: EF1287FD-3150-4777-875B-9E257DF834D8
CrashReporter Key: fe9516a078f6b5e19dab3fba4408e5e57348a3e2
Hardware Model: xxx
Process: xxxxxxxxxxxx 
Version: 2.1.16 (2.1.12)
Code Type: ARM-64 (Native)
Parent Process: launchd 
Coalition: com.xxxxxxxx.xxxxxx 
Date/Time: 2017-07-25 11:08:58.3086 -0700
Launch Time: 2017-07-25 11:08:57.1636 -0700
OS Version: iPhone OS 10.3.2 (14F89)
Report Version: 104
Exception Type: EXC_BAD_ACCESS (SIGABRT)
Exception Subtype: KERN_INVALID_ADDRESS at 0x0000000000000000
Triggered by Thread: 0
Application Specific Information: