I thought,'Maybe those little bugs again', so took off outside screen and blasted it with a can of compressed gas for cleaning computers. The result was a surprising ball of fire and some smoke, but also I heard the refer going 'clickety click' several times. Repeat blast from can and repeat result, more ball of fire and more clicks. I read the can, 'Do not use where it may ignite', (I know - 'Duh...') so maybe some of that ball of fire is the can, but it seems really disproportionate for the gas from the can and I presume there's propane igniting there, too.

So, please educate me.

Is the gas burner area in the refer hot to the touch? It could be the gas is running just fine but the refer refrigerant has been lost via a leak. Happens to all these absorption refers eventually, the refrigerant is ammonia and is corrosive. 

Ball of fire sounds more like the flue is blocked. There could possibly be a wasp nest in there. Remove the top vent cover. Take off the slanted T shaped flue cap and pull out the wire containing the flat spiral part. Shine a light in the top. Can you see the light at the burner? If so, then it is likely clear or only partially blocked. If not, then the flue is blocked. If it is, then clear out the blockage, reassemble, and try again.

As for the burner, if you take the gas line loose from it, there should be a small disk shaped piece in it with a tiny hole in it. Clean that with 93% rubbing alcohol or denatured alcohol. Do not poke anything through the hole. If that disk is missing, then you need to get one STAT.

If cleaning the flue and burner don't work, then it is possible that the refrigerant has leaked. Check the simple things first though. BTW, the compressed gas used in those cans of computer cleaner are flammable. My advice on cleaning is still valid, but the ball of fire was from the cleaner. It is much like holding a lighter in front of a can of hair spray and spraying. It is a home-made flame-thrower.