### ERROR edge #9085 is open (red).
### ERROR edge #9087 is open (red).
### ERROR failed to build collision geometry.
### ERROR failed to import collision bsp.

Some where on my map there are 2 open edges(red)! How do i find them?

wrl.

If you aren't going to elaborate and actually be helpful, then don't post. You didn't realize that a 3-letter response was neither helpful, nor impressive to anyone?

As for the error: which version of max are you using? Some newer versions don't support importing wrl's. Basically, when you export a map and tool finds errors during compilation, it spits out a .wrl file in your Halo CE root directory. You can then import it to your 3ds scene (make sure to only check off the box that says something like "import geometry," you don't want the import to change anything in your scene).

Then it's as simple as selecting and finding all the pieces that were imported - which will be in the same place as your open edges.

Alternatively, if you can't import wrl's, or you just want to avoid open edges in the future, convert your model to editable poly and use border selection (press 3) to see where your model ends (aka open edges).

weld all verticies at a value of 0.01

Click on the [+] in the top right of the view, go to xview and click on open edges.

Now you can see where the open edges are!

I fixed it. Seems like i accidently created a face in the wrong way messing up the normals.