Every time I want to enter the online tell me what is in the title of this conversation and does not let me and check everything from beginning to end and everything is fine please help

PS: I have the license Demo

You must use the username that you used when you first installed LFS. You can change your racing name in-game, but your username will always be the same.

..

It's because you are temporarily banned from the master server, probably because you have been banned too many times.

By the way, I think the error message should be more descriptive when someone is master banned - "username not found" is a bit misleading in this case, imo.

very thanks for all