This is a good example of how important it is to use single ply/marine TP.....as little as possible, and to hold the paddle down for several seconds after each flush in order to keep from making "paper mache" on the floats.
Can't say for sure with yours, but on the latest versions of the Tank Watch system, if the float that turns on the red light fouls in the "full" position, it removes power from the vaccuflush pump. This system logic is in place so one does not try to flush into an already full holding tank. But if a fouled red light is all that's wrong, you just lost your head until repaired. Not a good scene....