I read that if there is bom to your UTF-8 it won't take umlot and other German character. I tried to clean up the UTF-8 bom from the file, but it doesn't seems to work.

I work with libreoffice to create the csv. I am on CBJUICE V2-3.1.6 with community builder 1.9.1 and joomla 3.1.5 .

I get error example:

AlexanderKlaußner Alexander Klaußner Email: alex@*********.org Password: could not be added
Error in register store: Please enter a valid username.

Attach is a sample of data

The German username may be a problem. My advice would be to try a simpler username perhaps just first name with a number on the end. Given the message, this error is coming from within the internals of Joomla as a constraint on the username.

You're right Joomla doesn't accept that username when I input it manually. It seems strange at this point, but I think I can only strip out all these character at this point

Or pick a pattern for user names names which is just the first x "standard" characters and a number. You should post a complaint in the Joomla forum. Perhaps there are settings that could be changed.

Yes will definitly check with joomla core as its seems quite limiting.

thanks again!