Here is how I got GearBox working on High Sierra with my POD X3 PRO. I tried this so many times I'm not sure about the exact procedure that finally worked, but was something like this. Make sure that your Line6 hardware is not connected while installing the packages.
Files used (downloaded from Line6):
1. GearBox 3.72.dmg
2. Line 6 Audio-Midi Driver 7.2.9.dmg (I read somewhere that this is the last driver to work with GearBox. I have not tried others except for the latest which did not work.)
3. You will also need to download and install Pacifist app from the web.
Please note that to get this working you need to turn off System Integrity Protection. You will be doing this at your own risk! System Integrity Protection is a security technology in OS X El Capitan and later that's designed to help prevent potentially malicious software from modifying protected files and folders on your Mac. You can read more about SIP from here: https://support.apple.com/en-us/HT204899
To turn SIP off:
- Boot you Mac to the Recovery System, holding the command R down during boot.
- Click the Utilites menu and select Terminal.
- Type "csrutil disable" and press return.
- Close the Terminal app.
- Click the menu and select Restart
(If you later want to re-engage SIP, repeat the steps and use the "csrutil" argument to "enable".)
Once the computer has rebooted:
1. Double-click the GearBox 3.72.dmg-file to mount it. You can close the installer window that opens.
2. Go to finder and navigate into Gearbox -> right-click GearBox.mpkg -> Package
3. Open folder "Contents" and then folder "Packages"
4. Then install the following packages manually
- GearBox AU Plugin.pkg
- Gearbox RTAS Plugin.pkg
- GearBox.pkg
5. Open Line 6 Audio-Midi Driver 7.2.9.dmg with Pacifist.
6. Open Line 6 Audio-Midi Driver.pkg and install all of the packages. I installed the Audio driver last since it needs reboot after installation.
7. Reboot your computer. If all went fine you should be able to connect POD X3 to your computer and launch the GearBox and start controlling your device.
If this don't work for you, I can't help you. I'm not that computer savvy. I only got this working by combining instructions from various websites.
