I have two ASP.NET Web projects (ProjectA and ProjectB). When class in ProjectA is instantiating a class of ProjectB which uses a resource file Blah.resx, I get this error:
I have a WinForms application with a single project in the solution.
Targeting .NET Framework 4.0
Using SharpDevelop 4.3 as my IDE
Sounds silly, but I happened to have the Logical Name property set to "Resources" on my "Resources.resx" file. Once I cleared that property, all works hunky-dory.
Normally, when you add random files as EmbeddedResource, you generally want to set the Logical Name to something reasonable, for some reason, I did the same on the Resources.resx file and that screwed it all up...
Hope this helps someone.