Hi
Have just updated to CB2.1 and have now an issue with the username field not accepting input. The message is "This input value is not authorized."
I reinstalled my last backup prior to updating to 2.1 on my localhost computer and the issue is not there and then updated to 2.1 and the issue is there.
Need help urgently as no one can register now on my site.
Thanks

I had this issue after upgrading to 2.1

I found the issue to be with the validation, removing 2 comma's from the end resolved this for me.
Now the end of my validation on username looks like this:

Solved.
Have removed the 2 commas that were at the end of validation string which seems to have fixed the problem.
Would the Joomla upgrade to 3.6.5 have had any affect on the issue as the commas were there prior to the CB update.
Thanks for your quick responses guys, much appreciated.

Posting this for others, should anyone else have this issue.

As a test I put the ,, back at the end and near the end, so I had these as the last 4 characters:

,,,!
,!,,

Both combinations fail.

I found the best way to resolve this and continue to restrict the comma, is to make the username more restrictive by changing the Authorized input to, "single a-z,A-Z,0-9,_ word"