HL2.exe Has Stopped Working - map specific problem

map problem gone wip thread, scroll down for a screenshot if you’re interested.

I posted this problem before and was getting somewhere, but the thread got moved to Help & Support, where it died; it recieved no replies since being moved…
So I’ve been making a gmod map lately in the Half-Life 2 Episode 2 engine and my map compiles fine and everything, but once in game, after moving to certain positions in the map the map will sometimes, not always, crash-to-desktop with the error “Hl2.exe has stopped working”. The map is about 20480x20480 on the hammer grid and consists mostly of a displacement-based terrain generated from a heightmap. There are a few points that could be useful to make about this:
-I run Windows Vista (yeah, I know…) and run the map with a smooth framerate
-I’ve given the map to two friends that both run win7 and one of them had the same problem yet the other didn’t.
-When I hide the displacement visgroup and compile, the error no longer occurs, but this could easily be because I can’t walk to any of the positions which cause the error (no point of reference). Even when compiling with the map cordoned off to 3072x4096 units around the spawnpoint, it still crashes in a certain place near this spawnpoint.

If necassary I will post a compile log, and if things get really desperate I’ll upload the map itself as a .bsp. Thanks in advance for any help.

Do your displacements use a power of 4? If so, don’t. Make it power of 3.

Good lord, that worked! thanks a lot Zyx. I’m thinking of turning this into a WIP thread if anyone’s interested, it’s very much early days now but I might update it if it gathers any interest. Have a screenshot to start with.

http://img153.imageshack.us/img153/7569/gmpinewood0006.jpg

It’s a good start. But the light seems a little boring. Is the light_environment set to pure white?

Nope, it uses the recommended values for that skybox which are 241 210 190, producing a sort of skin-colour.