I have the same issue on w windows machine. Tech support told me there is a grounding issue with the OT. Some people are affected by it. This is what I was told to try (though it didn’t work)
1 - Power on the OT
2 - Set the OT to USB mode
3 - Power on the computer
If the above doesn’t work…
1 - Before you turn on the computer plug the OT into your mixer using the audio cables. Apparently the mixer may solve the grounding issue.
If the above doesn’t work…easy stuff
1 - Try different ports ((if you have got them) and only have the OT plugged in while you follow the top three steps.
2 - Buy a CF Card Reader (which I ended up doing)
3 - Elektron said they are planning a revamp of the OT USB chip that we can retrofit into existing OT’s. It’s not out yet and I don’t know when this will actually happen but it is worth putting in a request to be notified.
4 - Dink a fine bottle of 18yr Scotch and drown yourself in your sorrows. It won’t fix the OT but at least you will be too mashed to care!
Good Luck! Let me know when or if you get this fixed!!