Used it last night. On Catalina intel using Kontakt 6.7.1 through 8.5.0 - all worked. I am sorry people are having hassles.

 

I've been having this same issue with KLU, it just up and completely stopped working at some point and I have been trying to retrace my steps.

I can't uninstall any library, nor can I install anything. KLU 2.4, attempting to install a library simply does nothing, and the older version of KLU simply gives me an "outofbounds" error, also doing nothing. I've tried everything from fresh install of Kontakt (8.5.0) and KLU, I'm thinking this has to be some sort of plist thing or a file out of place, or -something- . I've been trying to fix it for a few weeks now to no avail...

Kontakt works just fine with all of my previously installed libraries, I can see them all in KLU, I just can no longer manage them.

I'm on Monterey 12.7.6, the "Add Library v3/4" tools don't even seen open or do anything, I've tried all the scripts, nothing.

really a bummer, the tool is fantastic when it works,