I cannot set conversion settings for Driver, what should I do?

If Driver's conversion task fails, it would cause configuration file path error in the registry, making the watermark and encryption settings blank.

Solution: 

Close Driver and delete the following,

HKEY_CURRENT_USER\Software\Zeon\Gaaiho\Gaaiho PDF in registry, then restart Driver.

Reminder: you may access the registry by entering "regedit" in the run box or search box