Cant add user to mysql database

[arserver]

Hello
When i try to add user to database i get that error " Warning! : No special characters are allowed! "
but whit root account I can

[Igor S.]

Hello.

For username you should use only letters or numbers or both. Also you can use: "-" and "_" .

Hello
When i try to add user to database i get that error " Warning! : No special characters are allowed! "
but whit root account I can