I have a wpf Application in which I am trying to reference a class library i have created. I have added a reference to the .dll And i have added the using statement to my fi
A few thoughts on this matter that you can try:
Check that a lower version is not calling a higher version assembly (e.g. .NET 3.5 project is not calling a .NET 4.0 assembly).
Clean -> Build (or Rebuild)
Manually delete bin/obj folders of both caller and calling projects. This forces everything to be built - the 'hard ' way. This may sound redundant, but has worked for me a couple of times.
Restart VS - sometimes, there is just no explanation.
Reboot - when nothing else works, give it a break and try again.