Error editing V12 project with V17

I went back to work on one of my old projects from Resolve V12 times. Not much success here, got into a Catch22 like situation.

Steps:
- Open project
- Relink videos to new location

- This then occurs: https://www.dropbox.com/s/04kiiohlafoom74/Error%20updating%20from%20V12%20project.mp4?dl=0

Only way out was to kill Resolve (at the end of the clip).

Any ideas?

Never had that situation, but what about first opening it with 15 and then progress to 17?
12 to 17 might never have been really tested.