I ran across the following incredibly annoying bug while building protection pillars like you see at gas stations to keep vehicles from hitting the pump. To see the bug in action start a new map then... Create a cylinder brush with 32 sides measuring 16x16 hammer units. Save the file and close it. Re open the file, hammer gives an error message about a corrupted solid and asks if you want to resave the map. Go ahead and do so. Hammer will crash. Reopen hammer and open the test map. The solid will be gone. Had this been an actual map and not a test map - every single static prop in your file would also be gone. Where does a bug report like this go in order to reach Valve?