First time: Witch Doctor. Wearing Mundunugu’s. In town. Cannot click Kadala, Waypoint, Obelisk, vendors, etc. CAN open inventory, follower, and leaderboard. Character still visible on screen.
Second time: Greater Rift. Level 55. 96% complete. Second map. WD died, but no “resurrect at corpse” etc menu. No monsters on screen. Just grave marker. Cannot click any part of screen.
Edit
Third time. Just completed GR. Attempted to click Orek - not possible. Clicked the following with no response: Obelisk, follower, vendors, stash. Could move around the map, could open inventory and follower, could not pick up items off the ground or out of equipment slots on either follower or self. Game eventually crashed out - maybe 2 minutes after this started.