I tried to initiate a merge and got a warning I’ve never seen before and cannot complete any advice would be great:
If you see this message again, check both profiles. If one of them is orphaned, adopt it, so you can approve the merge on one side. Then check the contributions of the other PM. If they are active, hopefully, they will approve the merge soon. Send a PM to the other person requesting they approve the merge. If you get no response, you can follow the process for the Unresponsive Profiles Managers which will require you to do a couple of other things, ie leave message on the profile of the PM, as well as request to be added to Trusted List of the Locked Profile. Wait a week and then you can send the form for the Unresponsive Profile Managers.