UPDATE:
In case it happens to help anyone else with the most obscure of issues:
A video codec was causing a conflict somehow.
Opening any video format- such as in media player resolves issue.
There is something in the build game routine at the very end that conflicts with some codecs if they are not loaded after startup at some point.-
So, once again- perfect performance from s4Real Lightmapping on 32 bit AND 64 bit!
It is so strange.
I have tried to replicate where the issue is coming from.
It does it no matter the quality setting.
x64 was working before.
It is now happening with regular vanilla and even a new install of 1.18.
I have the3 mscv files in place.
It was able to render before, so in general dbpro is not the issue-= but something somewhere it is reading has to be off.
It makes it through the entire process, and just at the end when it is outputting files it starts to generate files folder and then blue screen of death.
Any thoughts truly appreciated. But still, main xp 32 bit making great levels!