there is no user language switch anymore. This is an upcomming feature. You can only select the main language in the control panel:
https://www.ubbcentral.com/forums/ubbthreads.php/ubb/showflat/Number/1811/page/3#Post1811

Translating can be hard, I know. I do it the following way:
I get beyond compare from scootersoft and compare the 6.5.5 files to 7.0. This way I do a new translation. In 7.0.1 where some no longer used strings removed.

You can exchange own languages here: https://www.ubbcentral.com/forums/ubbthreads.php/ubb/postlist/Board/17/page/1


my board: http://www.dragonclan-forum.de
my hobby: http://www.biker-reise.de
Ich kann bei Fragen zu UBBthreads in Deutsch weiterhelfen oder es zumindest versuchen