[MrEyes]

Originally Posted by veenuisthebest

1. User registration options->Username Regular Expression -> Enter ^[A-Z0-9 ]+$ that would allow alphanumeric characters including space. Read (?) for more details

I might be wrong as I haven't used regex for ages, but the one given will not allow for lower case characters. So I think it should be something like this:

^[A-Za-z0-9 ]+$

Or this if you want to allow . (full stops)

^[A-Za-z0-9. ]+$