Answer
When you receive the below error, you need a multi-user site license to activate Foxit Editor with the iFilter plugin on the server.
The error is caused by the iFilter plugin being pushed out with the software. The iFilter plugin built into the .msi package is meant for desktop use, so it triggers the error.
If you use the user-named licenses, you can follow the solution below to remove the PDF iFilter plugin from the Foxit installer.
Solutions:
1. Change the Foxit Editor to remove the iFilter plugin.
a. Open the Foxit PDF Editor Setup.
Go to "Control Panel\Programs\Programs and Features" ->Select "Foxit PDF Editor" ->click "Change".
b. Select "Entire feature will be unavailable" option under "Foxit PDF IFilter".
2. Customize the Installation package via a MST.
You will need to create a .mst file through the Customization Wizard with the setting to disable the iFilter plugin.
Please see here how to use the Customization Wizard Tool to create a .mst and deploy it: https://kb.foxitsoftware.com/hc/en-us/articles/360040241172-Generate-transform-MST-files-via-Customization-Wizard
Please see here to find the Customization Wizard Tool version compatible with your version of the Foxit Software: https://kb.foxitsoftware.com/hc/en-us/articles/360040659931-Available-Foxit-Customization-Wizard-Tools-for-Foxit-PDF-Editor-for-Windows-version
The specific setting you are looking for within the Customization Wizard tool is under Features. You will want to select iFilter and set it to "Entire Feature Will Be Unavailable"