Ok, I got my Visual Studio Android emulator working, see prior blog post. Now focusing on IOS debug-run with a connected Mac. I got the following error.. Severity Code Description Project File Line Suppression State

Error Could not copy the assembly '/Library/Frameworks/Xamarin.iOS.framework/Versions/10.4.0.97/lib/mono/Xamarin.iOS/mscorlib.dll' to 
'/Users/davidyardy/Library/Caches/Xamarin/mtbs/builds/App1.iOS/820c43b5a93f812c648bedcbb5cd7ad5/bin/iPhoneSimulator/Debug/App1.iOS.app/.monotouch-64/mscorlib.dll': 

Access to the path 
"/Library/Frameworks/Xamarin.iOS.framework/Versions/10.4.0.97/lib/mono/Xamarin.iOS/mscorlib.dll.mdb" 
or "/Users/davidyardy/Library/Caches/Xamarin/mtbs/builds/App1.iOS/820c43b5a93f812c648bedcbb5cd7ad5/bin/iPhoneSimulator/Debug/App1.iOS.app/.monotouch-64/mscorlib.dll.mdb" is denied. 
App1.iOS   

I made sure that my Mac Agent was connected and all seemed good there. I opened the with Xamarin Studio (on the Mac) and had the exact same error. Ok so this error is not isolated to only Visual Studio (or worse yet just 2017). I now have the problem on both Mac and Windows.

This could be related to the beta release/channel of Xamarin. Ok, so the resolution was found with this bug/resolution posted here

https://bugzilla.xamarin.com/show_bug.cgi?id=52113

The full workaround is:
sudo chmod 0644 /Library/Frameworks/Xamarin.iOS.framework/Versions/Current/lib/mono//.mdb