Assigning users and groups to a role can time out when there are a lot of users. In the example case there are over 9000 users in the database, and thus the page times out when selecting users. Adding maximum execution time (and memory) makes the change possible, but this is not ideal.

How to reproduce:

• Create 10000 users (with a script)
• Go to a role
• Assign role to group
• Observe timeout

One solution would be to limit the number of user loaded, but ideally the listing would be done dynamically (possibly using the Universal Discovery Widget) instead of loading all options to a dropdown.