i installed buddypress plugin and one more plugin with shortcodes for buddypress. Also, I installed a code snippet tool, but i delated it now.
I tried to deactivate the first two plugins. Nothing happen with the login-window. It is still not shown. I think, it is because of:
i tried to do this on my own:
https://www.8theme.com/topic/change-my-acoount-text-to-username/#post-208597
Regards
Joey :/