Just updated to the new Visual Studio Mac 7.0 (3146), along with Xamarin.Android 7.3.0.13 and Mono 5.0.0.100 and now our app crashes on launch with an assertion from inside Mono:
[] * Assertion at /Users/builder/jenkins/workspace/xamarin-android/xamarin-android/external/mono/mono/metadata/icall.c:5160, condition `dest' not met
[libc] Fatal signal 6 (SIGABRT), code -6 in tid 3246
I went back to Xamarin.Android 7.2.x and it's working again, so looks like 7.3 is causing the problem.