# Error: There was a problem loading the activation library

#1

The following error messages may occur when upgrading from an older version of Lumerical software. Typically it is possible to simply install the new version without manually un-installing the older version first. However, in some cases the automatic un-install fails, resulting in these errors.

There was a problem loading the activation library. Code #.

Such problems can be resolved by:

1. Close the error message by selecting ‘NO’.
2. Open the Control Panel > Programs and features, and un-install the software (ie. FDTD Solutions)
3. Go to C:\Program Files\Lumerical\ and ensure the product folder (i.e. FDTD) has been removed.
If it is still present, delete the entire folder.
4. Reboot your computer
5. Re-install the new version of the software.

For more information, see Lumerical FlexNet license manager error codes.

FDTD.exe is not running