Tricky one, this is the internal error message we get from Roslyn:
error CS1705: Assembly ‘YoutubeHelper’ with identity ‘YoutubeHelper, Version=220.127.116.11, Culture=neutral, PublicKeyToken=null’ uses ‘Google.Apis, Version=18.104.22.168, Culture=neutral, PublicKeyToken=4b01fa6e34db77ab’ which has a higher version than referenced assembly ‘Google.Apis’ with identity ‘Google.Apis, Version=22.214.171.124, Culture=neutral, PublicKeyToken=4b01fa6e34db77ab’
So easy fix obviously is to either downgrade your helper project or upgrade the VL files.
How we can forsee such a thing and tell you about in a nicer way I’m not really sure yet. Didn’t make “pop” yet in my head ;)
I did however improve the exception a little so it shows at least the first (there can be many) internal compiler error - will be in an upcoming release.
Good question, I can only guess to be honest. Apparently the JIT compiler of .NET either didn’t care, or (since it’s very lazy) it didn’t run into any conflicts as it found all the methods it was looking for. C# on the other hand seems to care. So would be interesting to re-build that setup in a plain VS solution and see how it deals with it. It does however make sense to complain about it. Two different versions of the same thing is always trouble.