Shame on me

Thanks to Benny who opened my eyes. Code generation with a protected constructor was the reason for the error. But now I was able to add a detail pref page for TestNG activation.
When Benny wrote the mail with the solution for my stupid mistake I planned not to code after work again. Today I broke my rule, but I have choosen a glas of red vine as my pair programmer and it seems to be a good choice :)