ZDoom

Fixed. This was accessing a global variable that only gets set after the first frame is rendered.

Huh, weird -- this happens to me too, so it's not just a one-off. Here's a crashlog:

[attachment=0]CrashReport.zip[/attachment]

[EDIT] In case it helps, if you start an episode with the GL renderer on and change it back to software in-game, things work fine (even starting new episodes). Some sort of first-time-init borkiness, presumably.

Just start a new game with the Carmack renderer to reproduce the crash.
Someone mentioned it @doomworld:
[quote] I just tried playing Eviternity with GZdoom 4.0 and it played flawlessly when using Hardware renderer. However, using software renderer resulted in a crash. [/quote]
https://www.doomworld.com/idgames/levels/doom2/Ports/megawads/eviternity