Hi, very usefull module

I have pretty many users on my website, so plenty of pages in user management page. After a certain number of user updates however (about 100 i think, so at any 2-3 pages), i got error on the screen with "operation not allowed. if the problem persists, please contact the site administrator"

After I reset permissions, from content options, got no more error and works again.

I was wondering, is there any way to select all users at one time and update them.

Thanks