Native Instruments have issued advice for those experiencing issues with Avid CoreAudio in Yosemite issues.

Yosemite is as yet unqualified by Avid, but this advice is for those users of Mac OS X 10.10 Yosemite who also use Native Instruments products with hardware dependencies.

In the advice Native Instruments say;

Disclaimer: This article describes the manual uninstallation of a third-party manufacturer component. Native Instruments cannot be held responsible for any damages to your system caused by following these instructions.

Products with a hardware dependency, such as MASCHINE, KOMPLETE KONTROL, TRAKTOR, GUITAR RIG, and Controller Editor will not launch when the AVID CoreAudioManager / Drivers are installed under 10.10 Yosemite. In stand-alone mode the application will freeze after launching, in plug-in mode the plug-in validation of the host program will fail, which might crash or freeze the host program or make the plug-in unavailable within the host program.

Native Instruments and Avid are working together to resolve this compatibility issue.

Follow these step-by-step instructions to temporarily remove the Avid CoreAudio driver in order to allow NI products to run properly under Mac OS 10.10:

Open the Finder and locate the following folder: Macintosh HD > Library > Audio > Plug-Ins > HALMove the “Avid CoreAudio.plugin” outside of this folder (e.g. to the Desktop).Type in the admin password when prompted.Restart your computer.

While you still can fully use Pro Tools without the Avid CoreAudio driver, it is not possible to monitor the audio output of any third-party application using your Avid audio interface. If you require this functionality again, you need to move the file back to its original location and restart your computer. In this case, the mentioned NI applications will stop working again.

As we have already said in earlier articles upgrading to Yosemite is entirely at you own risk until Avid qualify their products for use with it.