It seems to be able to open the file now without crashing, so I can repoint to the correct OCIO config. In this case, I have the ocio config folder renamed to test while the preferences still point to the old location. The color is obviously not being corrected by OCIO, but Affinity Photo does not tell you that it can't find a config where you told it there would be one. A message saying that there is no valid config OCIO at the location set in preferences would be a good thing to add. I will try a few more things to see If I can crash it. But it looks like critical issue if fixed.
Thank you for following up. Affinity Photo's OCIO support and ability to use all your major functions in 32-bit color is a big differentiator from your well known competitor. I think you will be picking up market share from 3D/VFX people who need these features.