My Gaaiho license became trial and I got "0x20020221" when trying to activate, why?

Symptom:

You are 100% percent sure you have activated the product and it has been working properly. All of a sudden, the license status becomes trial and you are no longer able to access the full-feature product. Worse, an error message “0x20020221” shows up when you attempted to activate the product again.

Explanation:

For Gaaiho PDF products, there are two possible causes:

1. You are using Driver’s serial number to activate Suite, or vice versa
2. You have installed Driver and Suite in turns which leads to incorrect data placement in the license file

Solution:

For cause no. 1, install the correct version and activate.

For no. 2, see the following.

1. Uninstall all Gaaiho PDF products in your computer
2. Delete the folders in the following paths
   (Windows 7): “[systemdrive]:\ProgramData\Zeon\Gaaiho\ZNSL” and “[systemdrive]:\Program Files (x86)\Common Files\ZEON”
   
   (Windows 10): "[systemdrive]:\ProgramData\Zeon\Gaaiho\ZNSL" and "[systemdrive]:\Program Files (x86)\Common Files\ZEON" and "[systemdrive]:\AppData\Zeon\Gaaiho\ZNSL"
   
   
3. Reboot the computer
4. Re-install the Gaaiho PDF product
5. Activate the product using the same serial number (read this article if you've reached the activation limit)