Could not find any resources appropriate for the specified culture or the neutral culture

Question

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:

Answer 1

Yet another cause: if your namespace has a hyphen ("-"), then it will build and run correctly, but the resource won't be accessible. Namespaces (identifiers) aren't supposed to have hyphens, but this doesn't appear to be enforced anywhere except in loading resources. This has burned me twice over the decade.