Just tried Hayne and Sao's latest suggestions. Everything worked in the Terminal, but unfortunately it made no difference to how much I could load into Kontakt. Surely this now suggests that the open file limit is written into the Kontakt software? If this is the case, could this help:
http://developer.apple.com/qa/qa2001/qa1005.html
or if not does anyone have any ideas?

Thanks again,

Andy.

I repeat my advice that you should ask the developer and/or the forums at the developer's site. There may be another way to accomplish what you are trying to do with the software that doesn't involve the huge number of open files. I.e. try to solve it by using the Kontakt application differently.

OK, fair enough. Thanks for all of the time and energy you've put into this.

Andy.

Fix for tcsh
 

Hi, folks...

I was running into a similar problem with simple scripts, running in tcsh. For whatever reason, the open file limits for tcsh were set to 256...quite a low number. Using the "limit descriptors unlimited" command (can also be placed in your .cshrc file), the number went from 256 to 10240. Getting beyond 10240, as discussed at length above, is a hairier issue. If you just need to hit the 4- or 5-digit regime, however, this is an easy fix.

So late
 

Hi there,

I am sorry that I am joining that late, but I have Kontakt, too... ;-)

So, at the moment I am really getting confused. I am using Logic with that Kontakt as an audio plugin. That error -42 comes up to fast, the cpu is hardly at 1/3 and the ram has also enough space (as andy b described above). So, I can't use my fast computer because of a software programming thing?! Has there anything happened about that topic? Is there a way around?

I tried that:
sudo sysctl -w kern.maxfiles=80000
sudo sysctl -w kern.maxfilesperproc=60000

... in the end but even that isn't enough. I have opened about 12000 Files within Logic, concerning EXS Samples and these Kontakt stuff, so it seems to have no effect at all, but the terminal says it is set to 80000 and 60000. I just need way less, but I thought who knows, perhaps that could do the trick.

OK, hard day for me, long post though, sorry! Is there any way to open that limit? I am running OSX.4.9

Regards,
Xcell

I can change these settings fine on my system. My only question is do you think this will help speed up Final Cut Pro? How can I tell how many files the application is using... I have noticed that even when rendering huge files with final cut being the only application open it still doesn't max out my 8 gig quad core... Is it possible to make it use all memory that isn't tied up by the OS...