Tool gets this right after is said 'building subclusters...' Here's the debug...
04.21.09 11:01:25 tool pc 01.00.00.0609 ----------------------------------------------
04.21.09 11:01:25 reference function: _write_to_error_file
04.21.09 11:01:25 reference address: 42ca20
04.21.09 11:01:25 Couldn't read map file './toolbeta.map'

Since I've never had this happen before, and it doesn't give anything in the debug wrl, I'm guessing that it's not necessarily a problem with the map, just that it literally doesn't have enough memory to use. The map might just be too big. I will try to optimize it, but in the mean time, is there any way to let tool.exe have more ram memory? I have 2GB total on my system and i know that there's more available for tool to use. If anyone HAS had this error before and fixed it, please tell how. Thanks!

Take a screeny of what tool says, since it didn't put it in the debug. You don't have any errors on that.
Edited by chrisk123999 on May 25, 2009 at 11:58 AM

C:\Program Files\Microsoft Games\Halo Custom Edition>tool structure levels\test\
island1 island1
Couldn't read map file './toolbeta.map'
building intermediate geometry...
building collision geometry...
reducing collision geometry...
building collision bsp...
reducing collision bsp...
verifying collision geometry...
verifying collision bsp...
building portals...
building render geometry...
building subclusters...
couldn't allocate subcluster.

That's what it said.
But I think I solved it. 1st I optimize it a bit. Didn't help. But then I added some portals and now it doesn't get that problem. (Though the portals have some problems, but I should be able to fix those). But it did successfully build the bsp when I added portals.

I'm pretty sure subclusters have to do with render only geometry, but I don't know.