Xamarin.Forms could not install package

Question

When creating a new solution within Xamarian studio I get this error

Could not install package \'Xamarin.Forms 1.0.6186\'. You are trying to install t

Answer 1

I have invested a lot of time trying all the solutions posted here, but none of them helped me... Here is the solution that worked for me (on Windows 10):

1.) Open your .csproj file

2.) Find the TargetFrameworkProfile entry

3.) This entry contains Profile78 for me, therefore I open the folder below

c:/Program Files (x86)/Reference Assemblies/Microsoft/Framework/.NETPortable/v4.5/Profile/Profile78/SupportedFrameworks

4.a) If the folder does not exist, then use one of the solutions posted here to install the PLC right on your PC

4.b) Unfortunately, ASP.NET and Xamarin don't like each other, therefore delete all ASP profiles from this folder. For me it was ASP.NET Core 5.0.xml. Obviously this will break your ASP.NET support in VS

5.) Restart Xamarin and have fun!

interesting reading about all that: https://forums.xamarin.com/discussion/52846/cannot-create-new-xamarin-forms-project-pcl-in-xamarin-studio-win10-vs2015