I don't know what happened, since I didn't change any settings or configuration, but Visual Studio 2019 (for Windows 10) recently started unexpectedly closing & unassociating my MainPage.xaml, MainPage.xaml.cs, App.xaml, & App.xaml.cs files. This happens mostly when I save the files, although which file(s) it happens to are not always the ones I am saving. My changes do get saved, and restarting Visual Studio 2019 reassociates the *.xaml & *.xaml.cs files, so no files are (to the best of my knowledge) damaged, but it is very frustrating to continuously reopen the files & not have them displayed correctly in Solution Explorer. Has anybody else had this problem? Does anybody know how to fix it?