Komplete Kontrol loading issue, apple silicon or vst2 to vst3

This is not a Komplete Kontrol error.

You are using an old and unsupported VST2 plugin.

Most probably, you used a VST2 version before, now you use a VST3 version but the presets were made with the VST2 version and the plugin does not support VST2 to VST3 migration.

Note: It will be much easier to get answers if you provide real information (for example, which plugin is it? which version? etc etc.) instead of generic talk where no one can guess what you mean.

Maybe you use an older Komplete Kontrol version?
Latest one is the 3.3.3, if you don't have it, please update.

Or maybe you are still using the VST2 versions of the plugins?

Check these options:

Make sure the above 2 options are enabled at Preferences → Plug-ins → Manager:

Make sure that this folder exists at Preferences → Plug-ins → Locations
and in the very rare case that don't exist, add it:

ok, here is your problem:

man, you have 3 Kontakts! 🙄

Don't you remove the older versions when installing new?
Are they all Players (demo versions?) or do you have a full version too?

Anyway, in any case please remove the oldest Kontakt (which is the first, the one without a number and probably Kontakt 6)… unless if it is your only Full version.

If all your Kontakts are Player versions, then keep only one! The latest, Kontakt 8

It is a common practice, since decades (at least among experienced users), the newer version always replaces the old.

On most cases, there is absolutely no reason to keep the older software.

There are exceptions of course, but they have to be somehow practical. For example you made a track years ago with version 6, which had a specific structure (or a unique sound) that they don't exist in the newer version, but this is very rare.

Also, technically speaking, in many cases, keeping old versions, while there are newer ones installed, might confuse the system and cause problems.

Back to your case, as i wrote, the "numberless" Kontakt,vst is the older one, most probably from Kontakt 6.

Now, if you try to open a newer library with this version, you will get a problem, because they are incompatible! I believe this is a good reason to remove the old version, isn't it?

Here is another case:

Some Kontakt 8 new style libraries are made for Kontakt 8. If you try to open them, even with Kontakt 7, you will get an error. Some Kontakt 7 libraries can not work with Kontakt 6 etc etc.

However, the newer application (Kontakt 8) of course can play all older libraries.

So, now you came with a problem and we are try to find it and help you. After some research and based on what you wrote, we narrow it down to Kontakt instruments and not VST's. But if you had, for example, only the latest Kontakt version, most probably there would not be any problem at all!

I believe you got an idea about what i mean. :-)

Now, to finalize this: I believe that your problem is that, an older Kontakt version is trying to open a library created with a newer version. So, in order to fix things you have to remove the older version. For start, just move it to some other folder temporarily and try to open the plugin/library that didn't worked before.

"Some VST working some others not"…

It will be really helpful if you actually write the names of the problematic plugin/libraries!