Me and my team have gotten stuck multiple times because of items that we could not pick up. In Designs of Duergar, after killing a monster a lever gets dropped. We were not able to pick up the lever, even after killing ourselves and taking the short rest. After 4-5 attempts at the mission, we eventually were able to collect it, but did it on the easiest level in order to save time because we were having to redo the mission so much (we were doing missions on level 6).

The same thing happened to us again regarding a bomb that was dropped by a monster in An Infernal Dispute. Once again, we were not able to pick up the dropped item and were not able to blow up the door to proceed with the mission. We are currently stuck here and have not been able to get passed it yet.