Okay so, I'm doing everything on the mod tutorials except made the rooms a bit bigger. I tested my lvl out after the first and second tutorial, I walked through the entire lvl and everything was fine. So then I made the cave and also started filling my rooms, nothing fancy just a few tables and chairs. Then on the fifth tutorial about navmeshing (i think), it sounded a little confusing so before I started I saved my work and loaded it up too make sure everything was still good and WTF?! I started in a completely different room then my marker, there was no floor, and all the tables and chairs were falling into the "big black pit of nothingness" lol....can anyone please tell me what to do? any info would be much appreciated!

When you saved it, did it ask you for a file name, or did it save automatically ?

i dikept saving under seperate files, but i got it now. Thanks!