I am using VS2015, R#10. None of the suggested solution worked for me. I deleted the contents of the bin folder of my solution and rebuild the entire solution, that seems to have resolved the issue. Before deleting the contents of the bin folder, I had tried suspending and resuming R#, doing clear cache from R# -> option -> general setting, and also manually deleting the contents from \AppData\Local\JetBrains\Transient\ReSharperPlatformVs12\v01\SolutionCaches.. Hope it helps someone.