Super Easy Fix !!!
Got Toneport UX2 (old red model) working with El Captian. Heres what i did. Google search line 6 driver version 7.6.7 download, open, install the driver.
Thats all you need to do. Now heres my story.
I've had a UX2 for about 9 years now. I hated it to tell you the truth. But now i'm loving it. I use Reason and don't really like to go outside of Reason. Reason is my choice of weapon. Thanks Reason ! Been with you guys since 2.5 ! I always hated Gearbox and line 6 monkey. By the way i didn't need them on this way around. By simply installing the 7.6.7 driver my system reckonized it. Install the driver, then open "system preferences" to check if the driver is there. It will be at the bottom of the window and say "Line 6 Audio-MIDI Devices" Double click the line 6 icon to open up "Line 6 Audio MIDI Devices" Then click on "Run Audio MIDI Setup" NOTE: This is a quick link to the mac system "Audio Midi Setup" The one thats found in >applications>Utilities>Audio midi setup. Thanks line 6 for the quick link !! I didnt know about that for years. From here you can check things like left & right stereo field to see if your system is performing properly. Also you have to right click on "Toneport" and check it to receive input (Microphone) and output (sound output). There will be little icons that verify the selection. Note: You can also set the system alerts like beeps and noises to go through the Line 6 interface. Back to the Line 6 window side of things "Line 6 Audio MIDI Devices" you can configure "inputs and recording" under the "input source" function. Also you can select what the actual interface shows on the meters by messing with the "Hardware meters show" function. No need to have the Gearbox Software. Or the Line 6 monkey updater ! No more monkeying around with those things !! Go straight to the mac system and check Toneport for ins and outs. Then go straight to Reason and check Toneport under audio !! Anyways thats how i got past the Gearbox and monkey. My system can configure those settings. I don't need additional software for that. By the way, I can still use my keyboard volume to adjust levels. I can also set levels on the hardware interface. And i can set levels on my monitors. I usually try to set the hardware and monitors to half way then go up and down as needed on my keyboard. I have a Mac Pro 2009 4.1 firmware upgrade to 5.1 with 3.46 processors on the way this week. Running El Captian 10.11.6. Ive added some images to help anyone interested