Last night I was running a sequence and everything was going fine.
Somewhere around 12:30am an imaged failed to download in the allotted time and SGP sent an abort command to the camera and SGP froze up. Well it did not freeze up per se, it continued to 'try' to issue commands but there were no responses. PHD kept running and the mount kept tracking until sometime that night it finally struck the pier and nearly ripped the usb cable out of the filter wheel. I am very lucky in that was all the damage done apparently. The CGX-L is a 'powerful' mount and surprised it did not rip the camera and wheel off the OTA.
I have witnessed this behavior before when running frame and focus routine 'looping' and sent a stop command. The camera never responds and SGP locks up requiring a power cycle to the camera and SGP to be closed and re-started.
The particulars: Mount: Celestron CGX-L, Camera Atik383L+, Filter wheel Atik EFW2, Guide camera: Loadstar X2, PHD2 ver 2.63, SGP version 2.6.023
Here is a link to the log file