Failed to convert files, and a message says "Gaaiho/Zeon license service is not started"?

Full Message:

"If Gaaiho License Service has not been started, please start it in Services Management, so the product can get the correct license information." There will often be a "Limit is exceeded" text popup that accompanies this.

Explanation:

Just like what is mentioned above, if the service has not been started, you will not be able to convert files.

Solution:

1. Type "services.msc" in "Run" dialog box

     2.  Find "Zeon/Gaaiho License Service" in the list and start the service (Note: if you cannot find the service, please re-install the product)

     3.  Reboot computer