I tried all possible ways, switching on/off, unplug the cable, wait a couple of minutes and then plug it back.
In this case the error message is generated because the upper main shaft sensor is not synchronized with the bobbin/hook. In my case the hook got misaligned after the nest was created (the magnet did not seat properly); the solution was to remove all parts (bobbin/hook) and put them back. It took me 14 hr to find the way to solve it, but happy to see my machine is working again.