@lorenb Usually this happens when switching node versions. The usb driver is a binary that needs to compile and depends on your node version. I've had success using both Node 4.x and 5.x, but I had to recompile the usb driver.
What is the output of
❯ which t2
Given that example I would then run this:
Then you should be able to run the following command:
And it should rebuild and
t2 command should work again.