Overview

When editing the license key for GFI LanGuard, it does not accept the new one and reverts back to the old one with an error 'Invalid license key!'.

Solution

1. Verify that the entered license key does not have any spaces.
2. Make sure that the license key is issued to the correct LanGuard version (i.e., you are not trying to use LanGuard 12 license for the installed LanGuard 11 version). If that's the case, upgrade the LanGuard following the Upgrading GFI LanGuard to the Latest Software Version article.
3. Ensure that the file toolcfg_license.xml (located in C:\Program Data\GFI\LanGuard) is not set to read-only.

Testing

Once the root cause is found and addressed, reenter the new license key. If the issue persists, contact GFI LanGuard Support.