We had the same issue at our company and used resharper build as a workaround for it - just enable it in resharper's options and everything will be working. Of course it's not ideal to use 3rd party tool for something so basic, but at least it doesn't stop the development..

We were getting this error just recently and it resolved it locally by installing the VSIX that was provided above. Unfortunately this did not solve the problem for us entirely as this was also failing in DevOps pipeline builds on iOS project. We discovered the root cause for this was that a HintPath to Mono was added to the main Xamarin Forms project file.

<ItemGroup> <Reference Include="Mono.Android"> <HintPath>C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\Common7\IDE\ReferenceAssemblies\Microsoft\Framework\MonoAndroid\v9.0\Mono.Android.dll</HintPath> </Reference> </ItemGroup>

Removing this HintPath fixed our problem. This is a far better fix than installing Alpha code IMO. Can someone tell me if it is OK to uninstall the VSIX without causing problems?

This issue has been fixed and is now available in our latest update. You can download the update via the in-product notification or from here: https://visualstudio.microsoft.com/vs/ Thanks for your feedback.