Adding or removing users can cause a 503 error

[RaywanS]

Hi team,

I have noticed an issue while adding/removing users (both at site level and folder level).

Basically, I just add (or remove) one or multiple users and click on "Confirm". As it take forevers (average of 10 seconds), my natural behavior is to click again few times on the Confirm button, which often leads to longer waiting time and then a 503 error, as seen on the screenshot.

We were able to reproduce it with @fflorent

[RaywanS]

PS : this screenshot doesn't show the 503 error but most of the time, it displays it in the error box