Custom Map[1km] crashes at 44-46%

Hi guys , i have a problem here.. probably my first time to encounter this.
i created a 1km map(navmeshed & set up for ai support..) , but i always get CTD with no errors in windowed mode(i always test maps in vbf2) at this 44-46% consistently at the "Collision" part. What could be the thing(s) that is(are) causing it?


I hope someone can help me(specially because it is my first time making a 1km map, excited :D)

-Heneral Luna