Photon flashing Cyan with Red Bursts

I’m having a problem similar to the one described here:

My photon is one I let some students use, and I don’t think it’s currently claimed under my account.

I’ve tried running (blinking yellow DFU Mode):

particle device doctor

(blinking blue listening Mode)

particle identify

and get:

Your device id is <My_Device_ID>
Your system firmware version is 1.4.4

Then When I try running (blinking yellow DFU Mode):

particle keys doctor <My_Device_ID>

I get the error:

New Key Created!
attempting to add a new public key for device <My_Device_ID>
Make sure your device is in DFU mode (blinking yellow), and that your computer is online.: Error sending public key to server: Permission Denied

Any ideas where to go from here to get this device up and running?

Is the Photon blinking yellow (DFU Mode)?
Are you running this from a directory with write permissions?
Are you logged in with CLI?

Thanks for your help, @ScruffR
Yes, Yes, and Yes.

I think the problem might be with the fact the the photon isn’t claimed under my account.