Failed to load sound "____whatever.what___", file probably missing from disk/repository

After the recent HL2 update, my save file got fucked up and for some reason that error keeps popping up for everything.
When I walk, it makes zombie groaning noises.
Hunters sound like headcrabs.
Basically all the sound is fucked up.

But when I just load up the map by itself, all the sound is normal. No problems whatsoever.
Is there anyway I can fix this?

[editline]4th March 2011[/editline]

Also lighting randomly fucks up too.
Flashlights, lamps, etc.
EX: Flashlight is turned on. Rectangular hole casts a rectangular shadow.
Move to the right by a little.
Now the whole room is illuminated.

another EX: Using flashlight under lamp. I’m looking forward while the lamp is far above.
A specific section of what is illuminated by the lamp; when I look at it with the flashlight, the light of the flashlight is gone.

Also the map related is gm_Atomic

[editline]4th March 2011[/editline]

Just checked the file again:
Actually the flashlight extinguishing had nothing to do with the lamp.

Updates often break saved games, your game isn’t broken when you aren’t playing in this save game right?

Correct.
I would start over but I’ve already invested a lot of time into putting furniture and nice little details into the map.
It would take forever to re-do it.

[editline]4th March 2011[/editline]

I should also mention that my other (much more older) save files have not been affected.

I doubt it can be repaired as you are hoping, you could just advanced dupe everything, or do a toybox save of it or something, might come good then.

How exactly do I do a toybox save?
How can I adv dupe a whole world?

I’ve only started playing with the toybox recently so it’s all new to me.

[editline]4th March 2011[/editline]

Forget it. Just found out how to toybox save.
Should mention though that for some reason toybox saves always creates the world with all doors duplicated over eachother. Know anything about that?

[editline]4th March 2011[/editline]

The toybox save is 20X worse than the actual save.
Combine stuck in the ground. Black doors. Duplicated doors. Missing Combine. etc.
So how do I adv dupe everything.

Image with errors:
[img_thumb] http://cloud.steampowered.com/ugc/596931038154797720/A17D27D485B416EBA4C82711D79596E33485D0CE/ [/img_thumb]

Image with (one of the many) lighting issues:
[img_thumb] http://cloud.steampowered.com/ugc/596931038154797332/C44DCB4470F776AB07833A6C9C00E1F0A69CA93A/ [/img_thumb]

snip