When installing a major Mac OS update over an existing one (not using a clean install), or when using Apple's Migration Assistant to transfer files and preferences from one Mac to another, you will often run into trouble with drivers not working properly, authorizations being lost or corrupted etc. When files are mixed between systems, or are transferred to a system they weren't specifically intended or created for, difficulty is always a possibility.
The suggesions below may help resolve these symptoms.
Note: Numark 4TRAK users - check out the suggestion here.
If your MIDI devices no longer work properly after an update...
- Empty the contents of the following two folders by moving their files into to two new folders on your desktop:
Macintosh HD > Library > Audio > MIDI Drivers
Macintosh HD > Users > [Your User Name] > Library > Audio > MIDI Drivers
Note: the second location above is hidden on Mac OS X 10.7 and above. To access it see these instructions.
These are the places where third-party MIDI drivers are stored. If they have become corrupt, or they haven't been installed correctly, removing them and starting over may help.
- Restart your computer.
- Try your MIDI device again.
If the symptom has been resolved, you should...
- Reinstall each of these drivers by visiting the home page for the respective device manufacturers. Note, if your MIDI device is Class Compliant, it doesn't require any extra drivers to be installed.
- Find and download the latest drivers for the product(s), and install them.
- Confirm all of your devices now work properly, then trash the files you had moved from your MIDI Drivers folder to your desktop.
Further Technical Support
The suggestions above should help you quickly determine if a product is functional, and to help you overcome common setup obstacles. If you require further assistance with product setup or have determined that the product is NOT functioning correctly, contact the Technical Support team or refer to some of the related articles below:
- Troubleshooting Class-Compliant USB Devices
- Troubleshooting USB MIDI devices on Mac
- Mac OS X - Problems with MIDI devices after an update