Actually, I'm at 520 such motor stall errors and climbing! I've tried to move the mount (via SGPro and SkySafari) and have encountered this issue every time. I've encountered dozens (hundreds) of such errors anytime now I try to move the mount. There are no unusual noises coming from the mount. I have not used the mount in about 4 weeks but nothing has changed since the last successful session a month ago. Here is image I took before it reached the maximum number of errors:
Mach2 with latest firmware
Power via PSVPW25A -- no apparent issues
Connected via TCP LAN with USB backup
What are my next steps?
PS: I had an issue with the mount earlier in which a couple of washers had come lose from the RA control unit but I sorted that out.