You don't say:
- Which version of KLAX you installed. Was it one with the new installer, the one that installs outside the sim, or an old one, that installs *into* the sim ?
- Which simulator you use.
In any case, try this:
- uninstall both sceneries, and reply YES to the question "Do you want to remove the Addon Manager" ?
- reinstall both, using ONLY the current version of the installer for both. Do not use any installers you might have downloaded in the past.