I was working on recoloring the JKA model linked above for personal use, but every time I try to examine it in-game, it doesn't take long for the game to crash due to an "Access Violation." These crashes seem to occur when the model is used by a (re)spawning entity or incinerated after/while being fragged; crashes also occur immediately after loading a new map while the model is in use.
I know that most of these crashes have occurred when I had "Force Player Models" enabled; map-switching wasn't an issue when I was the only entity using the model, and one of my first couple of crashes triggered the moment I toggled the setting. Other player models, for both JK2 and JKA, have been tested with Force Player Models enabled, but none so far have reproduced the crash.
I have a bunch of crash logs for portable Win-x64 clients, builds 1.4.1 and 1.4-54. The maps I have crashed on were official; crashes occurred both when connected to a dedicated server and when running a server with the client.
Edit: Tried it in both normal JK2 and JKA; JK2 crashes as described above, but JKA seems to keep running without issue.
Edit 2: It looks to me like a lot of my crashes occur when the model's LOD is supposed to change; at least one of the torso surfaces disappears after some distance and an Access Violation occurs when I try to close that distance. The disappearing torso can also be observed in JKA but does not cause a crash there.