The ArcGIS Portal Organization seems to default to 0123456789ABCDEF somewhere. I can view it in editor tracking as it is prepended to the user name and I can also see it in the REST interface. Is there any way to change it?
Wow, that is interesting. Seems that this is the default for many other Portal IDs out there (doing a quick google search showed me a lot of interesting things). I am not sure but have you looked at this article for configuring the advanced settings:
I did find that link along with the large number of public deployments using that ID. It does not seem to explain anywhere how to change it. I am using 10.2.2 Portal and the documentation only shows 10.3 and 10.4 anyway.
Hmmm, that's a good point. I was hoping that would be an easy fix but I guess the documentation does not state where or how to change it, unfortunately. Sorry about that. This might require a support inquiry to Esri.
BUG-000086539 - When Portal for ArcGIS is federated with ArcGIS for Server, signing into the REST API administrative endpoint with a portal token displays the administrator username as ‘0123456789ABCDEF::’.
I know this happens when Portal and Server is federated. But it seems like in your case, this is interesting.