The ClassFormatError message is somehow misleading:
Exception in thread "main" java.lang.ClassFormatError: Illegal class modifiers in class test: 0x209

It looks like the modifiers of class "test" is 0x209. I think
a better message would be:
Illegal class modifiers in class test's InnerClasses: 0x209
or
Illegal class modifiers in class test's inner class Enter: 0x209

It would have saved a lot of time and debugging the VM to discover it was really
the inner class whose modifiers were wrong.