If something goes wrong with the license for GibbsCAM you can recreate it by doing the following. 

.  Delete the current license file and run the Registration Tool to recreate it.

The license file should be stored in:
C:\ProgramData\CAMBRIO\GibbsCAM\LicenseData\140.0 (v14.0.21+)
C:\ProgramData\3D Systems\GibbsCAM\LicenseData\140.0   (v14.0.17 and older)


Run the registration tool. Start- Gibbscam-registration tool