Warnings after update Xamarin Studio

Question

I just updated Xamarin Studio to the latest version (Xamarin.Android Version: 4.6.4 (Business Edition)) and I'm receiving a lot of warnings after the update..:

/Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets: Warning: Reference 'mscorlib, Version=2.0.5.0, Culture=neutral, PublicKeyToken=xxxxx' not resolved (TrackandTrace.Droid)

/Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets: Warning: Reference 'Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=xxxx' not resolved (TrackandTrace.Droid)

I already tried to remove the reference and re-add it without any effect.

Update: Even if i create a new project I receive 2 errors right from the start.. These errors make unable to build android projects.

Answer 1

I also experienced that after upgrading(I believe you tried in release mode) try to change your appropriate architectures in your applications properties (if not sure, select all 3)

Answer 2

Try following (only a guess):

Find following Path: C:\Program Files\Reference Assemblies\Microsoft\Framework\.NETPortable\v4.0\Profile\Profile104\SupportedFrameworks

In that directory add a new xml file with that name: "MonoAndroid, Version=v1.6+.xml". And the following Content:

<?xml version="1.0" encoding="utf-8"?>
<Framework DisplayName="Mono for Android"
  Identifier="MonoAndroid"
  Profile="*"
  MinimumVersion="1.6"
  MaximumVersion="*" />

Restart Visual Studio and try it again.

Answer 3

I had a similar problem when I tried updating a couple of weeks ago. Some useful advice I got from the support/bug fixing team:

Inside Xamarin Studio, click Help-->Check for Updates. Change the update channel from Stable to Alpha (or Beta) and try that version. If that doesn't work, you can roll back to a previous version by going to:

http://store.xamarin.com/account/Products and clicking on Show Recent Releases on the bottom right.

Answer 4

Add Microsoft.AspNetCore.SignalR.Client.Core NuGet package to your core project and that should fix the issue.

See "Can not resolve reference: `System.Memory`" or "Could not find `System.Memory`" after update to Visual Studio 2017 version 15.8 Preview for details.