This applies to Tensor serial numbers 108-066999 and lower when trying to update firmware by using the UpdateFirmware.command script (check the inside of your pedal or see this article if your serial number is not visible). Serial numbers 108-067000 and later use a different bootloader and are not affected.
If this is the first time you have used the Terminal application (or our update script), it will ask for permission to access files on a removable volume. Click OK. That should allow the update to finish successfully.
If you click Don't Allow, or previously restricted access, the update will fail with the "Operation not permitted" error described in the next section.
Symptom
When you run the fie UpdateFirmware.command script, a Terminal window opens to execute commands that copy the firmware (.bin file) to your pedal. The firmware update fails with this error message (the version number will vary):
cp: /Volumes/TENSOR/tensor_1.2.2.p.bin: Operation not permitted
FIRMWARE UPDATE FAILED
Solution
Default security settings in recent versions of macOS prevent the Terminal from accessing removable drives like the Tensor.
Open Apple menu-->System Preferences.
Click Security & Privacy.
On the Privacy tab, select Files and Folders from the list on the left.
On the right side, scroll to the Terminal application.
Under Terminal, select Removable Volumes. If other folders are listed (Documents, Desktop), you can leave their setting unchanged.
After that change is made, you can re-run the UpdateFirmware.command script and it should work. After updating, you can reset your Security & Privacy settings if you wish.