Cannot Controller to Designer Account

When trying to link the controller to my designer account I get the error but I am not sure why, I have no controllers showing in my designer and everything appears to be running.

“No controller with the given MAC address was found or maybe it’s linked already.
Please start your controller before linking it, make sure it is not linked yet and that it has internet access.”

I read elsewhere on the forum that this step is not necessary, however I cannot successfully add the controller to the iOS app either. Any idea as to the solution? I have had openremote working in the past. Is there somewhere that I can unlink controllers and start fresh?