ISSUE: Can not run maps compiled in Hammer.
So I'm sitting here mapping, compiling, and testing my map. Everything is as it should be. Then, I compile once more, portal loads and *BAM* - it closes.
And that's the problem. Every single time I compile to test the map, portal will load and then exit right away - no errors, no nothing.
What I've tried so far:
- Starting Portal then Opening the map (still crashes)
- Restarting Hammer
- Restarting Steam
- Restarting my Computer
- Verifying Integrity of Game Cache (on tools and games)
- Removing and Reinstalling "Source SDK", "Source SDK Base" and "Source SDK - Orange Box"
- Reseting Game Configurations
- Deleting and Restoring GameInfo.txt files
Any help is appreciated - I'm running out of Ideas.
does it crash when you load the map or when you load portal? (when opening portal seperate from hammer)
When the newly compiled map loads.
I can run Portal and any map that was compiled before now.
sounds like the map is corrupt or something, maybe you added something to the map that isn't compiling right and portal is having a fit. If you have alot of outputs from triggers using the I/O system (i think 50 per sec is the limit) portal crashes. Try compiling everything except the newly added part of your map and see if it will load that.
*ps* i don't have any real experence with this so if anyone walks by who has some exp, feel free to step in 
I had a similar problem with a map not loading and crashing when I had a malformed brush. It was a brush with a concave surface I made using the point move tool. If you have a brush with a curve or more than the average 6 points try removing the brush from your map and recompiling.
I tried deleting everything that caused/received an input/output and nothing changed.
Also, I was pretty sure I didn't have any malformed brushes, but to be safe I deleted anything that wasn't an obvious rectangular brush - no improvement.
try making a new/different map and see if you can compile/play that. nothing super fancy, just make sure your hammer is FUBAR.
This kind of issues often happen when you used the Vertex-tool and Hammer mashes up the brush shape because the vectrices aren't placed very well, resulting in, as stated before, malicious shaped brushes. Those are a real show-stopper in compiling and testing. The exact problem-causing brush should be announced somewhere in the top of your compile log, if this is the case.
The same can happen when 2 surfaces, both with glass textures, cover each other. Make sure that that doesn't happen, if you make a glass panel existing of multiple brushes, make sure the faces that cover each other are textured in nodraw. You wouldn't see them anyway.
"Duct Tape is the answer."
Well, after trying a whole bunch of crap and reading all over the place, it looks like the issue has been resolved - but doesn't make any sense.
Turns out it was a paged pool memory issue. The odd thing is, I rebooted numerous times without the issue being fixed, and had changed NOTHING on my system while mapping over the past few days.
The info that helped me is here: https://support.steampowered.com/kb_article.php?p_faqid=150
Thanks for the feedback guys, it kept me going.