I had the "Spark Home has Stopped" message appear when the A3 was tuned to a corrupted channel. To correct, I removed the channel from the list.
I disconnected the coax (in case the signal was causing the error), but in my situation the message still appeared. I then repeatedly pressed the channel up or down remote key during the A3 restart. Once it was tuned to another channel, I deleted and added the channel again without problem. Not sure if I messed-up on manually adding some PIDs or what???
Hope that helps!