Steam thinks Portal 2 is 127MB, crashes before title screen
So I tried Portal 2 for the first time in a while. (It worked a few months ago or whenever I last played it was.) Did the whole converting to a more efficient format deal. Now when I launch it, it gets as far as the various logos and the load screen, but then it just crashes before the title screen.
Properties says it's only 127 MB. I checked the Common folder and it's the full 11 GB. Verifying the integrity of the Steam cache says one file fails to verify and redownloads, but that doesn't fix anything. When I verify again, the same thing happens.
Google tells me someone had this problem and fixed it by quitting Steam, deleting the appcache folder, and starting it up again, but that didn't help me. I also tried manually deleting the 11 GB game folder and that didn't help either. Uninstalling and reinstalling still gives me a 127 MB file to download. (I've since restored the appcache and game data folders.)
Does anyone have anything else I can try?