I've been trying to pinpoint when the missing AB trail issue started to happen and I get it even since XT0124
I've confirmed it happens with -no_glsl too and with/without window mode.
It's fixed already, don't worry.
It was just a simple load order issue. The graphics were being paged in like they were supposed to, but since the trails are setup on a ship when it's created, and ships are created during mission parse (before page-in), the textures weren't loaded at the time the ship was created. That's also why simply doing a reload fixes the problem, since it can easily re-assign the textures again since they remain loaded.
I fixed it by breaking the AB trail setup into it's own function, so that it can be called both which a ship is created, and when textures are paged in. That makes sure that it will always work.
Regarding the other problem, it is actually supposed to crash there with a debug build. Well, it's an Int3(), which causes a program interrupt. As the 3.6.9 debug warning reports, it's simply a table error and not a code issue. Warning popups are still disabled in stable CVS builds, since I'm still working on the new code for that, otherwise you would have gotten the exact same message in newer builds.