Does it appear that your license has expired? Ensure you have installed your permanent license. If you have not received your permanent license you may need to request it. A temporary license may also stop working if you have changed the time and date settings on your computer, and you will need to contact your account manager to request a new license.
Do you see a message, "Duplicate license file.”? This is not an error, and FME should still run correctly. At times, an unlicensed FME will try to contact our licensing server to see if there is a license available for that serial number. If so, it automatically licenses itself. This message is caused when you try to manually license FME using the same license it has already automatically obtained for itself.
Do you see a message, "FME Licensing Notice Your current license is AutoDesk Map. This application cannot be used with current license..."? You may be using a Training or Generic license. Using your file explorer, navigate to C:\ProgramData\Safe Software\FME\Licenses. Delete every file in this directory except the file fme_license.fmelic. Restart FME Workbench or the FME application you were attempting to use.
Do you see a message, "Administrator permissions are required to license FME..."? The licensing assistant may need to be run with elevated privileges. Right-click on FME Licensing Assistant, and select Run as administrator.
If you have confirmed the machine key matches your license file and still cannot license FME, or you see error code -500 or -501, in rare cases a registry entry may be blocking your license. Run regedit and navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Safe Software Inc.\LICENSE. Delete the key called LICENSE.
Do you see a message, "License quota exceeded..."? Contact Customer Support.