Portal glitching HELP!

[Ih8pkmn]

So I decided to play Portal again. Everything worked great until test chamber 16. At that point, sentries and cubes began falling through the floor when I picked them up, and floating around as if they were in water. Is there any way to fix this? Please tell me, because now The weighted Companion cube is falling through the floor, too.

Also, for some reason, the "transmission recieved" achievement isn't working for me. No new radios are spawning in the game. What's going on?

 

[SL33TBL1ND]

Check the integrity of the game cache, if that doesn't do anything send a support ticket. If you get nothing helpful from them delete everything in your steam folder except the steam executable and the steamapps folder which is the catch-all trouble shooter for steam.

 

[Tharwen]

I've had this before as well (I think). Just reload a save file where it wasn't happening, then it should be fixed.

 

[Ih8pkmn]

Check the integrity of the game cache, if that doesn't do anything send a support ticket. If you get nothing helpful from them delete everything in your steam folder except the steam executable and the steamapps folder which is the catch-all trouble shooter for steam.

erm.. this may sound bad but... how exactly do I do that?

 

[SL33TBL1ND]

Check the integrity of the game cache, if that doesn't do anything send a support ticket. If you get nothing helpful from them delete everything in your steam folder except the steam executable and the steamapps folder which is the catch-all trouble shooter for steam.

erm.. this may sound bad but... how exactly do I do that?

Right click on the game in your steam list, say properties, local files, verify integrity of game cache.