Issue

You receive the message "The MediaSeal decryptor tray is already running, please check your system tray or alternatively the MediaSeal decryptor could be running as a headless system service.

Cause

MediaSeal Decryptor is already running and only 1 instance is permitted to run at a time.  You are trying to open MediaSeal Decryptor when it is already running.  The application may be running as a headless service, or running your account or under a different user account.

Resolution

Quit MediaSeal Decryptor from under the account where Decryptor is running. 

Or

Stop the MediaSeal Headless Service