So, I guess it was some
other guy whose handle is "sportflyer" posting the exact same problem...
You can try just deleting your existing Google Voice configuration, then upgrading the firmware per my instructions, then adding the Google Voice configuration back again. If it doesn't work, then yes, factory-reset the device and start over. It will only take a few minutes. As for
voip.ms, as long as you know your
voip.ms SIP account and password, you can also use the OBiTALK portal to automatically set up your
voip.ms account. Just click the desired SP1 oor SP2, configure GV on one of them, then click the other SP, and instead of selecting Google Voice, look down at the bottom of the web page for "OBiTALK Compatible Service Providers", and click "Next". On the next page, click "voip.ms", fill in the simple form with your SIP credentials, and you're done.
I would
not follow azrobert's instructions to backup and / or restore your device, given that it has very old firmware on it, and also old/invalid GV config data. Just start over. It's not that hard.