Reports of trying to register but every username entered is invalid

[ara4n]

I assume this is the ILAG path somehow getting stuck after the user tries to specify an existing or invalid-character username. I tried to reproduce it on the normal registration path and it was okay.

[ara4n]

My guess is that this is due to the horrid case sensitivity feedback, which is very cryptic in terms of complaining about the capital letter.

This is then a dup of #5833 but would be good to confirm.

[lukebarnard1]

Yep, confirmed this is a dup of #5833