New antivirus license giving the error message "Please enter a valid anti-virus license"

Updated on Feb 20, 2026

When entering a new anti-virus license, I receive the following error message when entering the new anti-virus license, "Please enter a valid anti-virus license"

If you purchased an anti-virus license and are not able to get the license validated, the most common cause is that your device requires a firmware update. Follow these steps to check whether you firmware version needs to be updated:

  1. Connect your drive to your computer.
  2. Open My Computer or Finder and locate the CD-ROM partition with the Kanguru icon.
  3. Open the CD-ROM partition and locate the file "version.ini".
  4. Open "version.ini" in a text editor and make a note of the current version number.
  5. Open a web browser and go to the following URL:  https://www.kanguru.com/community/knowledgebase/announcements/current-client-and-firmware-versions 
  6. At the top of the page is a list of the Latest Defender Client Versions. Locate your device in the list and check your current version number against the latest version number. 
  7. If the version listed on the support site is newer than the version currently on your device, go to the following URL to download the updater for your device: https://www.kanguru.com/community/knowledgebase/docs-category/software-downloads-and-updaters 
  8. Once you have successfully updated your device to the latest version, try entering your antivirus license again.