The default name of a team is "team of (yourname)"

When yourname, due to one reason or another, is invalid as part of team name, you can't create a team like that.

In your case, I'm guessing there is something with the character set that causes problems. Nonstandard characters are cool and stuff but it can cause all sort of problems.

You can, however, create a team manually by opening the team interface and create a team with a different name.