@mjb183
There is an FAQ article about this error, which you can check for possible solutions. But, normally, this issue occurs on HA core, venv or docker installations, that have issues with the access rights to Bluetooth. In your case, you are running HA Os, which makes it difficult to run most solutions. Can’t remember that I have seen this issue on HA OS before.
You can install the SSH & Web Terminal add in in HA to gain access to the terminal, although the terminal is still limited (as in, you can’t run every command). In that way, you could run some of the tips in the FAQ. Otherwise, check this issue on github