i finished a map and tried to build the structure in tool but it gave me this error:

C:\Program Files\Microsoft Games\Halo Custom Edition>tool structure levels\nprac
e nprace
No More Errors For Tools By: {TLS}Udie
building intermediate geometry...
building collision geometry...
reducing collision geometry...
building collision bsp...
### ERROR couldn't build bsp because of overlapping surfaces (orange).
### ERROR couldn't build bsp2d.
### ERROR couldn't build leaf.
### ERROR failed to import collision bsp.

i ran it in toolio and it gave me this exception:

C:\Program Files\Microsoft Games\Halo Custom Edition>toolio structure levels\npr
ace nprace
This Tool was hacked by DEElekgolo.
building intermediate geometry...
building collision geometry...
reducing collision geometry...
building collision bsp...
### ERROR couldn't build bsp because of overlapping surfaces (orange).
### ERROR couldn't build bsp2d.
### ERROR couldn't build leaf.
reducing collision bsp...
EAX: 0xFFFFFFFE
EBX: 0x00000001
ECX: 0x0012F2B8
EDX: 0x000002CC
EDI: 0x0012F2B8
ESI: 0x00000000
EBP: 0x0012F190
ESP: 0x0012F180
EIP: 0x7C90E514, C3 8D A4 24 ?????
EXCEPTION halt in .\import_collision_bsp\reduce_collision_bsp.c,#208: surface_in
dex>=0 && surface_indexsurfaces.count

according to it, i have a overlapping surface, but i cant see any

Import the wrl.

something is wrong with your model. if you know how, check for open/overlapping faces in max, or optimize it using the optimizing tool in max. that sometimes helps.