I just installed SP1 for VS2010, and since then I get error messages from Resharper for stuff that used to work and be ok for Resharper (5.1) before.
The error messa
I had this problem in spades in my multi-project VS solution. Tried Julien + Andrew's solutions and they did not resolve the issue. But everything compiled just fine and worked as normal -- it was simply the "Errors in Solution" that kept showing the errors (which also showed up when you looked at the code in the right-hand-ReSharper-margin).
It turns out I had inadvertently deleted the web.config file in one of the solution's web projects during some version control operations. Who knew that thing was important?
I restored the web.config file, cleared the cache and deleted the R# cache directories and then rebuilt all of the projects individually and the issues went away.
Phew!