License gone after upgrade

I'm not sure if I'm understanding your issue correctly but a common cause of updates gone awry is the Service Check Date in the license. Depending on the Service Check Date in your license, you may need to manually reactivate the BIG-IP system's license on the F5 License Server. Per K9412: The BIG-IP release matrix, the release date for BIG-IP v14.1.0 is December 11, 2018. That means the Service Check Date in your license needs to be that date or later.

To check your license's Service Check Date from the command line:

tmsh show sys software | grep "Service Check Date"

If the Service Check Date is before December 11, 2018, then you'll need to reactivate the license yourself. (The system does not do this automatically without at least being told to do the reactivation.) If you don't have stable GUI access, you can reactivate the license from the command line. Follow the instructions here: K2595: Activating and installing a license file from the command line If you do have access to the GUI, then you can do a manual reactivation there a lot more easily than from the command line.