DescentBB

This started happening all of a sudden, I have no idea what I could have done wrong or what files could I have messed up.

Basically as the title says - whenever I try to open a level converted in dle-xp to "Vertigo", Rebirth exits immediately with no error message and I can't play. This occurs before getting to choose the difficulty level. I do have all the files needed for Vertigo and the expansion mission runs just fine, so I have no idea what might be amiss. Any clues, please?

You can try enabling "-debug -verbose -safelog" arguments in your game INI file and try re-opening again. Then after the crash you might be able to find some error in your gamelog.txt file that might help you find the issue. If the game already crashes before the difficulty selecton there already might be something wrong when it comes to load the mission files in general. But without an error it's almost impossible to say.

Also usually Rebirth begins to spit out error messages if something goes wrong. Sometimes they can be pretty indescriptive but the thing is: if the game does *not* spill an error message by default the code probably breaks at some point due to something extremely unexpected case.
So I'm interested to see that myself so I can at least make Rebirth tell what's wrong in the future. So you could just mail me that level (you find my mail address on the Rebirth site).