I've just ran into this error. I solved it to edit the version field of the module that was giving me the error in the table mdl_modules. It might not be clean, but it saved me from having to delete the complete database of this site.
Lesson
Version mismatch: lesson can't downgrade 2005110200 -> 2005060900 !
Гэтае абмеркаваньне было заблакавана, таму вы болей ня можаце адказваць на яго.