Still chipping away at the Survival level. I solved a problem with the flow in the nav mesh - it kept giving me flow errors, but nothing was popping up when I ran 'nav_trouble_report" from the console. I had an area marked PLAYER_START, all areas were marked FINALE and BATTLEFIELD. I finally tracked the problem to the "goal" nav area it was using by combing through the log of the nav_analyze. In survival maps without a checkpoint, the area closest to the center of all the nav areas is used as the goal, and it turns out that the goal area it chose was on the (player inaccessible) roof. So I added on a new nav area to shift the center back onto a flat surface, and that fixed the problem. It seems like there would be an easier way to do it, but this one worked for me. Besides that, textured a few areas and moved some props around. I'll keep at it!