Problem with UserRegistration

Hi all, first time here but i cannot make up my head around a problem about the UserRegistration. Unitl yesterday all was fine, i can register users freely till i've done two thing:

1 - i've used the remove user to remove 3 users, with the remove user provided by foswiki.

2 - i've installed the UpdateAttachment.

Till then, the registration form cannot register the username. I don't know why.

I've already uninstalled the UpdateAttachment but the problem is still there, i've done some damage removing users?

Foswiki run on Ubuntu Server with Apache2.

-- DarioBergamaschi - 27 Jul 2016

I doubt that removing users with the ManagingUsers form has caused any issues. And it's pretty unlikely that UpdateAttachmentsPlugin is causing issues. We use it all the time on foswiki.org. What do you mean by "cannot register" ... Does it fail with an error? is anything logged in the apache or foswiki error logs? Could the ownership of critical files changed? (Which might have happened if you used the CLI scripts to install the plugin.) We n eed a bit more information to go on.

-- GeorgeClark - 30 Jul 2016