it's crazy that in 2017 some modern windows software crash or don't want properly just because I have the character "é" in my user name
@Siphonay because usernames must not have non-ASCII chars. 'Siphonay' would juuuuust work fine for that, and you can use your real name properly as your user full name.
@problemo yeah, alphanumeric:
something like /^[A-Za-z-_][A-Za-z-0-9_]+$/