Based on the details of your issue, it appears that after manually changing the OS drive, there are still old paths remaining in the Windows Registry. We recommend that you clean up the Windows Registry by deleting all entries associated with “Navigraph Hub.”
You can perform this cleanup manually or use a third-party application like CCleaner to assist you.
Please let us know if you continue to experience issues after cleaning the Windows Registry.
Essentially it got me to change the the letter of the drive back to M - install then uninstall FSHub then change the name back to E and install the hub again and it worked perfectly