This should be done after uninstalling some PreSonus drivers and software.
Use this process if you were instructed to do so by PreSonus Support or by the directions in another KB article.
Apple recommends the following steps to be taken when troubleshooting any FireWire related issue:
Repair Disk Permissions
- Open Disk Utility program ( Located in: Applications > Utilities )
- Select the First Aid tab - Select the system drive on the left panel (Typically, this will be labelled "Mac HD")
- Click Repair Disk Permissions
- When "Permissions Repair Complete" is displayed you may Quit the Disk Utility
* You should run the tool again until the scan returns no errors.
- If your FireWire audio interface is attached then power it off before proceeding
- Shutdown (power off) your Mac
- Disconnect all USB, FireWire, or Thunderbolt devices. If your Mac is a desktop model then you will need to leave your USB mouse and keyboard attached
- Locate the following four keys on the keyboard: Command (⌘), Option, P, and R
- Power on the computer and immediately press and hold the Command (⌘), Option, P, and R keys
- Continue to hold the keys until you have cycled through two start up chimes
- Release the keys after the second chime
- You will hear a third chime and then your Mac will boot to the desktop
After following this process you will be ready to try testing your FireWire device or install driver software for your audio interface.
Shutdown your Mac before reconnecting your FireWire device. You should always avoid connecting or disconnecting the FireWire cable while your computer or FireWire audio interface are powered on