Old projects aren't loading Komplete Kontrol correctly

Were the old projects saved with VST2 plugins? You would need to run in Rosetta mode to have them load correctly and will have to then switch them all over to vst3 and re-save.

You'd save plugin presets then replace the instance of said plugin and load previously saved preset. Not the most difficult thing but could be tedious - especially if you have plugin chains in your KKs also.

So if you had a KK instance with a Massive patch loaded in then you'd want to save the massive preset from the massive save menu (not a KK nks patch). Then replace KK add Massive VST3 versions and load in the preset / patch you just saved.

Hope that makes sense.

Note that with Logic I guess you just keep the same AU KK plugin because Logic ;) So you'd just need to swap out the vst2 Massive to a vst3 as per example above.

Yep, it is a pain but if you are on mac, that is the hand you have been dealt. macOS running Apple Silicon requires everything to be updated to "AS Native" code and with VST2 now being discontinued, most DAWs (and Komplete Kontrol) drop VST2 support altogether since most devs will not update the VST2 plugins.

So yeah if you open in Rosetta mode you should be able to copy the settings of the VST2 plugin to a duplicated track with a VST3 version loaded. THis could take you a looooong time to update many projects but as mentioned, export a preset for each track and at least you are also making backups..... Where you will have a headache is those plugins that may not (and may never) offer a compatible VST3 version because remember, even VST3 is not compatible unless it's been updated specifically with Apple Silicon code.

One reason I am happy to be on Windows for my productions, I have unfinished work dating back 15 years!

Yeah the NI content should all be fine as that migrates. Some plugins will auto switch from VST2 to VST3 but many do not or if they do, automation you have recorded may no longer work at all.

Unlikely to see a VST3 version of Xpand2 any time soon. Pretty sure Air Music will just revamp it and release it as a new/different plugin. People have been asking for them to release VST3 versions of their AIEP collection since before M1 were even a thing.

The new instruments they ahve released as part of the MPC Collection range are pretty well performing and my hope is they will release new versions of Xpans, Hybrid, Vacuum Pro and Loom II. Still so many cool sounds in those, but I purchased all those plugins years ago when they flogged them off for like $5