A possible resource loading bug in Beta5
It would appear that the 2006 JDoom pk3 based mod, entitled "Netherworld", that can be found here works under 1.8.6 but crashes 1.9 Beta5 at map start up with a Segmentation Violation;
Or here under in this group of maps;
A little bit of digging and I believe I found why the mod was crashing 1.9 Beta5;
1.9 Beta5 was not properly reading the sprites out of the mods resource wad in the pk3's auto folder. I was able to run the mod without issue on 1.9 Beta5 when I ran it with said wad being loaded from outside the pk3 instead of inside.
This could suggest that a resource loading bug of some sort has appeared in Dday since 1.8.6.