I think this issue happened after I upgraded from 5.0.2 to 5.0.4. I’ve got the RT debug log going to collect data & see if I can find it but wanted to post here as well.
Some (so far) users are getting a “Permission denied” error message on their web page after they add an update to a ticket. The error message appears in the yelow banner where you see “Correspondance added”, etc. It looks like mail is still going out/etc., but we can’t explain how this is happening. No admins here have admitted changing any user permissions.