When generating one of our WSDL's some generated classes contained an invalid package name because it contained a reserved keyword. The namespace in the WSDL contain the word 'Case'. The XML elements get generated such that the package name contains `._case.`. But the WebServiceClient and the WebService get generated with `.case.` in the package name (without the underscore) which is invalid syntax.
I have created a demonstration of the issue on GitHub: https://github.com/BobLuursema/cxf-bug