Looking at the PGP Encryption Server Logs (Symantec Encryption Management Server), the following errors may appear:
client request [internal user XXXXXX]: <DownloadKey>
client request <AuthenticateInternal> returning fault -11286 (authorization failed for this operation)
failed authentication for internal Encryption Desktop 11.0.0.1042 user (null) from [192.168.1.149]
connection from 192.168.1.149
The reason for this is typically because you had clients that were previously enrolled to the PGP Encryption Server, but their user account has since been deleted.
In order to fix this error, find out which machines were associated to the IP and locate the system and corresponding users and re-enroll them.
Once they are enrolled, this will re-establish authentication to the PGP Encryption Server.
For more information on re-enrolling, see the following articles:
180181 - Re-enrolling PGP Encryption Desktop for Windows clients (Symantec Encryption Desktop)
181366 - Re-enrolling PGP Encryption Desktop for Linux Clients (Symantec Encryption Desktop)
155714 - Re-enrolling PGP Encryption Desktop for macOS X clients (Symantec Encryption Desktop)
If further guidance is needed, reach out to Symantec Encryption Support for additional assistance.