UBB.threads PHP Forum Software Community Forums UBB.threads 7 Version 7 Support New members posting not allowed

Hi Still having problems with a member from about 5 years ago,I don't know where to find a solution about the user names changed ?is this a setting or a toggle in the set up menu , where would it come from?
I have resent passwords and everything looks good in the profile but he says he can not log in. He can not log in to change "mystuff" Thanks for your support.