@Ch4...
I'm not doing anything beyond opening the file, Building it and then clicking the Run button. Literally. That's all I'm doing lol. I wish there was something else I could say I'm doing at this end that might provide a hint, but there's nothing else.

Also.. per Uhrwerk's suggestion, I uninstalled the program, deleted the folder, reinstalled everything from scratch and tried again. This time, I also created a new project (outdoor project via the project wizard). Once the project was finished and it loaded the map for me, again I built the map, clicked on the "run" button and, again, I get the same error, the error in main.sys, only it only happens once with a clean new project build.

I also opened up the 'loop' map under the car demo game and, similarly, clicked on 'build', then 'run' - left all settings at default (as with the new project) - and still get the crashing.

One thing is different this time, however. It still gives 3 error windows, however, now only the first one says 'crash in main.sys'. The second two come back reporting error in "init_baum1".

So, that's at least something different from before, though I still have no idea what that means or what's causing it.

While it could well be some kind of weird compatibility thing or whatever, it's nothing I'm physically doing at this end. I'm not modifying anything. I'm not touching a thing. I literally click on 2 buttons: Build, and Run. That's it.

Thanks.

EDIT: I did some searching and found this explanation for the error code I'm getting:

"A function of your script crashed. The usual suspects are accessing an empty pointer, accessing a non-empty pointer to a removed or nonexistent object, or performing an invalid operation such as dividing by 0. Crashes are only indicated in the development engine. The distributable version will not issue an error message, but just try to recover from the error and terminate the function.
The name of the erroneous function is displayed in the error message, followed by the 3-character sys_marker (if any was set), so the bug should be easy to find in your script. If you get a crash right at startup or level loading, a damaged sound, image, or model file might be the reason. Another possible reason is a wrong setting of the DEP (Data Execution Prevention) in your Windows system configuration that prevents running scripts."

So that's a clue. Perhaps there's something missing that didn't get installed correctly or at all. I can try figuring that out, I suppose.