Printer stops, then G-Code Terminal repeats 'Read Thread Has Exited' indefinitely

'Read Thread Has Exited' messages that recur in the G-Code Terminal is indicative of a lapse in communication, perhaps due to some electromagnetic interference (EMI).

Check that the cable you're using to connect the printer is relatively short and isn't being physically crossed by power cords or any other cords that might cause unwanted signals to be accidentally transmitted to the printer. Even relatively small spikes in power could reset the controller board in some printers.