When attempting to perform PGP Whole Disk Encryption, you receive a PGP notification that The functionality you have requested requires a license number from PGP Corporation. Please click Upgrade...
A PGP Desktop license is used to enable the functionality you purchased and set the expiration of the software maintenance. Depending on your license, some or all of the PGP Desktop features will be active. You must then authorize the license for PGP Desktop either manually or online.
This notification can appear in PGP Desktop for various reasons.