While creating a new user the email address disappears after saving

Nextcloud version (eg, 20.0.5):
Operating system and version (eg, Ubuntu 20.04): Open SUSE 15.2
Apache or nginx version (eg, Apache 2.4.25): 2.4.43
PHP version (eg, 7.4): 7.4.6

We are running two instances of NC, one for testing an one for live services. Both are running on the same versions since october 2020.

For about three weeks the mail address entered while adding a user disappears after pressing the Add User-Button, but only in the live system. Testing environment works as expected.

Changeing the empty mail address field after creating the user and entering the respective mail address works fine.

Log and error log do not contain anything.

I suspect that any chached things might be broken in the app_cache.<instanceid>-Folder on the live system.

So some questions:

Is there a possibility to recreate the contents of this folder?

it’s obviously an error on our live system, but I don’t have an idea where too look for the reason. Does anyone have an idea?


Found the cause.

In our productive system the parameter newUser.sendEmail was set to “no”. Don’t know why. On March, 1st adding users worked without problem, on March, 8th it didn’t. Possibly problems with our Active Directory (we are having bot local and LDAP users) we had between these dates might have triggert a bug to set this. Anyway, I can’t reproduce it.

sudo -u <userid> php occ config:app:delete core "newUser.sendEmail"

helped and fixed the problem.