Powell,
You are likely right that Error 1 is a coincidence and probably has nothing to do with the sense board wiring. Lately, I get Error 1 almost every time I turn on the display. I have to disconnect the batteries, reconnect and it will finally work after several repeats. (until the next time I want to ride).
It's not worth the time I'm spending on it. I'm going to give up all but the motor. I will likely open the motor hub, disconnect the controller and remove if possible). I'll bring just the phase and hall wires out to a external 48v1000w controller. That will bump the top speed and it should make a solid bike reliable bike. Still a bit heavy for my taste, but a lot lighter the stock bike.
Best of luck to Easter3 and Wandyr with their Lithium conversion. If you need any of the parts I'll be discarding, contact me.