Prophet1 wrote:"server connection rejected. Invalid username."
That's not a certificate error, that's because you've got characters in your username that your server thinks are invalid. If you haven't changed anything, it's probably empty - this is okay when you have a certificate that matches the account, because the server will just force you to use the username that matches your cert. Pick any username that matches the regular expression set in username
setting in Murmur.ini. I forget what the default is, I think it's only English-alphanumerics, no spaces.
Once you've done that and can connect, you'll want to connect as superuser
and delete your old account. Then you can connect with your original username, re-register, and go through the process of giving yourself admin again