Hello PETE-C,
We understand that you're not able to update the Panasonic Tether software, on your Mac. We'd like to provide you with a few steps that may be able to further isolate the issue and correct this behavior:
1. Restart your Mac. This may seem like a simple step to take, however, it refresh your Mac and the software. On your Mac, choose Apple menu > Restart.
2. Start up your Mac in safe mode. Completing this step can help you identify whether issues you’re experiencing are caused by software that loads as your Mac starts up. Your screen may flash and load slower. This is expected behavior for this mode: Use safe mode on your Mac
3. Verify if the issue occurs in a new user account. This will allow you to determine if the behavior is specific to your account or if it is a system wide issue: Add a user or group on Mac
Thanks for connecting with Apple Support Communities.
Best wishes.