From the Microsoft support page:
This problem occurs if you use a localized resource that exists in a satellite assembly that you created by using a .resources file that has an inappropriate file name. This problem typically occurs if you manually create a satellite assembly.
To work around this problem, specify the file name of the .resources file when you run Resgen.exe. While you specify the file name of the .resources file, make sure that the file name starts with the namespace name of your application. For example, run the following command at the Microsoft Visual Studio .NET command prompt to create a .resources file that has the namespace name of your application at the beginning of the file name:
Resgen strings.CultureIdentifier.resx
MyApp.strings.CultureIdentifier.resources