[Classic] How to detect when group members change or raid roster changes?
 

I tried registering for the events PARTY_MEMBERS_CHANGED and RAID_ROSTER_UPDATE but neither of them are ever triggered.

PARTY_MEMBERS_CHANGED seems to not even exist anymore as an event in the classic client as it throws an error when I try to register this event.

RAID_ROSTER_UPDATE just seems like it never is called.

Any ideas?

Those are both removed long time ago, the new one is GROUP_ROSTER_UPDATE. I think you also need GROUP_JOINED and GROUP_LEFT depending on what you're doing but not sure.

The Classic client is based on the 8.1 API. There are some things removed, reverted back, etc. But most things like events, secure handlers, etc. will be as they are in BfA.