An issue occurs when trying to join another block, and when arriving, you can no longer accept client orders and the party is missing.

I believe the cause of this bug is because you don't join the party until after you've loaded into the area, therefore if someone fills the spot while you're in transit, you're left without a party and incapable of accepting client orders.

The only way to ctop this from happening is if you leave the block completely and check quests again.