damn, no, i havent! But i did had something similar once when creating continental17. The game just started to ctd after launch. I had to completely redownload/install the game to get it back to work, but after that, no problems in terms of modding or anything. No idea where it came from or what fixed it. HL:A seems to have some issues that turn up here and there. My install atm does also act up by simply not "closing" the game after "closing" it. It just remains somewhere in windows and only really closes when force-quitting steam. Got me 1700hrs of recorded playtime without realising it XD