Hi Maru. Your question: "Is this some very old scene re-rendered with 1.7?" made me think of a reason and solution.
I'm using a customized maxstart-file, that actually could contain old Corna references. So this is what I did to get rid of the *.hdc reference:
- restarted Max, to be sure the maxstart file was loaded (checked the assettracker to see if the *.hdc was missing - it was)
- changed the render from Corona to Mental Ray
- saved this as "maxstart"
- restarted Max, to be sure the maxstart file was loaded (checked the assettracker to see if the *.hdc still was reported missing - it was NOT)
- changed the render from Mental Ray to Corona, and made my own settings
- saved this as "maxstart"
Now everything is nice and clean :) :)
Regards