Don't know if it will help in this case but I've managed to open problematic files by unchecking the "Execute script nodes" checkbox found under General Options in the "Open" window. Hopefully that could work for you. And to state the obvious: save as more often!
you can also open up the script editor before you load the ascii scene and see if it gives you a line # with an error before it crashes. Then yo ucan see if anything fishy shows up on that line.
The scene just contains a lowpoly mesh, nothing complicated at all :/ I had a look at the script editor and it said " cannot perform polymerge on selection" about 5 times before it crashed, which is wierd... Will post some pics up of various things later.
May not do anything, but you can try opening the scene and pressing escape (esc) repeatedly. Esc should cancel any script Maya is running. For instance, if you accidentally hit "Mesh > Smooth" on that 15 million polygon sculpt, you can hit Esc and Maya will stop trying to smooth it. Rendering? It will stop rendering. So…