If people are already in a party can still be invited and join another group. The popup is the same as the one for the guild invite or the expedition queue. It’s silly that a player can missclick a “F1” to join the another group.
Fix this and put a popup mechaninc. Make a new popup:
If the player A is already in a group make a new popup for the player B inviting the player A. Show to the player B that player A is already in a group and can not be invited.
Make popup colours like:
- Green popup invite for PvE groups.
- Blue popup invite for PvP groups.
- Red popup invite if people are already in a group.