I have Visual Studio 2015 Enterprise and discovered that I cannot compile almost any of our existing 2013 projects. Further investigation reveals that Visual Studio 2015 isn\'t
If you are doing with Visual Studio 2015 Enterprize.kindly remove Old Xrm dll's and Add new CRM 2016 SDK Xrm Dll's Build the project also change the .Net Framework to latest.
After build the project Generate System Fakes Assembly we will get
mscorlib and system.Fakesjust remove this line <Add FullName="ConcurrentDictionary"/>
on both files and build the project