I'm on 10.15.7 and 6.7.1 (MacBook though). It's been solid for me.... One thing you might do before installing 6.7.1 (if you don't clone as a backup - which you should always run before updating something mission critical like Kontakt),
This is a very good advice for anyone, It is a small issue but can really save a lot of headache,
Of course the issue is you need two good quality SSD for local Disk C: if your on Windows,
you will will find your system is running rock solid until you get the push to update then it is possible for things to fall apart, this can be your OS or any music software eg DAW updates, plugins, and samplers players and host.
It is very difficult to keep up with what is being changed in your OS update or host, sample player, DAW and it is quite difficult for developers to nail every bug when keeping up with OS updates sometimes making a system crash inevitable.
Your first good quality SSD should already be used in your machine, your Second good quality SSD should be your stand by for a direct copy or clone, I find EZ gig cloning software very good for this,
So if you want to try out an update, first copy your existing SSD C drive and have on stand by then run through your updates and stress test it, if you run into issues just swap your SSD out for your copy and continue your project from where you left off, this is far better than trying to find your way out of crash city.
You may find that i stressed good quality SSD as i have found cheap ones can get bad clusters and that can contribute to your problems
This may be a little OTT but if you value you project this practice is a get out of jail card guarantee
Cloning a drive is very quick around 20 min to 45 min so its worth putting this in practice, it saves time and saves confusing post, as every one will not have the same issue