We do a lot of NextCloud installs, and use PHP-FPM + chroot for maximum security. This gets tricky though, and one of the more obscure gotchyas we’ve run across is trying to create a new user or set a user’s email address and getting back “invalid email address” despite the address being, well, valid.
Another issue which we later discovered was related was that the user list doesn’t update automatically like it should when adding a new user. The new user doesn’t appear unless you manually refresh the admin page.
After a lot of debugging and careful logging we saw this error mixed in with a lot of other things:
PHP Call to ICU MessageFormat::format() has failed: U_MISSING_RESOURCE_ERROR
This was breaking the user-list AJAX code, which was why the list wasn’t updating.
With that piece of information I discovered this GitHub issue, specifically this comment: https://github.com/nextcloud/server/issues/2162#issuecomment-262338666
The solution? Copying
/usr/local/share/icu from the system into the chroot1. With those files in place no more error and the admin’s user list updated correctly when adding a new user.
Still having problems? We can help, just give is a shout!
1 Path given is for FreeBSD operating systems, Linux path is likely