Amateur smoker here. My second smoke with a Masterbuilt 30 - first one (brisket flat) went perfectly. This time I found a nice whole packer and short ribs. I set up everything to spec, lit the AMNPS with a torch, saw the flame, closed the door. Per other posts for adequate air flow the wood chip loader is out and the top vent is open. For the first 2 hours I see TBS. At 2:30 I start to see billows of white smoke which I have read can cause a bitter bark. I open the door and the AMNPS is totally ON FIRE! I run to get the fire extinguisher and put it out before my whole apartment complex goes up in flames. All right, so I already feel like crap because 1) I assume I can't eat the meat anymore (can someone confirm this? It was an ABC extinguisher) and 2) I nearly burned the place down. Will someone tell me what I did wrong here that produced the flaming AMNPS and the billowing white smoke? Thanks in advance.