Thursday, December 20, 2012

Error 21 CA0055 : Could not unify the platforms

After a recent upgrade from Silverlight 4.0 to Silverlight 5.0, I started getting this error from Visual Studio 2010

Error 21 CA0055 : Could not unify the platforms (mscorlib, Version=, Culture=neutral, PublicKeyToken=7cec85d7bea7798e, mscorlib, Version=, Culture=neutral, PublicKeyToken=7cec85d7bea7798e) for '[path to Silverlight project dll]'.

Took me a while to track it down, and I found the solution to my problem in this post.

Being that we don’t use Code Analysis, I just turned it off on my Silverlight project.


But if you do use it, you’re going to have to run the command line arguments as the post suggests.

Tuesday, December 18, 2012

Error 17 Unknown build error, 'An item with the same key has already been added.'

I recently got this error after doing a code merge. No source file, no line number, just the project name and nothing else to point me in the proper direction to rectify my issue.

After much searching I found the answer to my problem in this post.

The post states this can occur if there are duplicate lines within a <ItemGroup> node in a csproj file.

I did a compare on my project file and found this.


I removed the duplicate line and everything was right with the world again.