Project Conversion from 4.6 to 5 Light Bake Failing

I am bringing a game from 4.6 to 5, and I have yet to successfully get the lighting to bake. I get stuck at Light Transport 7|11 every time, and a ton of asserts about executing external light transport failing.

Is there something I need to do when coming over to 5 that I am missing? I am trying now with non-directional maps and light maps size set down to .1 scale in lightmap, but I am concerned the quality is going to be terrible.

I have searched the forums, and so far it sounds like the new lighting is just bad (or hopefully broken, because then it can be fixed). I really just want to recreate the old results in 4 as much as possible, but am starting to get very discouraged. Any help is very welcome.

Paste your lighting settings and let’s see if we can help…