Hey FM Squad! Was getting back into blender 
and I started running into this error that was costing me about an hour of troubleshooting time between generating the map, tossing it onto the server, and testing it:
Invalid fixup, address is neither virtual nor physical?
What ended up being the issue was a bug in sollumz ability to generate the NATURAL .ydr binary files. (probably a bug to fix at some point)
As a fix, I simply took the .ydr.xml file from the gen8 output folder (gen9 probably works too) and manually took that into the Codewalker RPF Explorer.
From there, exporting the .ydr file worked just fine and had no issues after that….
Just wanted to share this as a google-indexable fix…