Invalid private key for encryption app

How to solve this issue:
“Invalid private key for encryption app. Please update your private key password in your personal settings to recover access to your encrypted files.”

Maybe you are still waiting for a reply: disable server-side encryption. I have version 18.0.6 installed and the same problem. If you have files thus encrypted, I have no clue as to what to do wexcept make sure they are decrypted…
The problem seems to exist for a very long time (2 years +).