PlayCDG Online program shows the error message “The program already is in the process of executing” and does not start.

The PlayCDG Online program is likely running but does not show up in your display due to a problematic configuration.
In the PC hosting the player, open the File Explorer and navigate to Documents > PlayCDG Online.
You will see a file “PlayCDGOnline.ini”. If not, click on View at the top of the screen and check the options “File name extensions” to see the full file names.
Delete the file “PlayCDGOnline.ini”.
Restart the PlayCDG Online program.
The program will start in the factory default mode.