Portal 2 CTD Windows "portal 2 has stopped working"

[Incryptx]

Portal 2 (and other STEAM GAMES) do not play after installed. SHADERAPIDX9.DLL and FASTPROX.DLL (both 32 and 64 Bit) seem to be in conflict. Taking posession and renaming FASTPROX.DLL will make the game work, but this causes WMI related problems for other Windows applications dependant on WMI.

This is clearly a STEAM dependant DX9 function as SHADERAPIDX9.DLL is only found in the STEAM DIRECTORY. STEAM is well aware of this bug, but for some unknown reason refuses or fails to fix it. This bug is also responsible for other STEAM games which CTD or throw a Windows "stop working" error.

It's not so much the game I have a problem with and would recommend, it's the fact that it is broken and still being offered for sale with no warnings about this bug or a solution offered by STEAM.

From what I have learned, this bug has been reported to STEAM Technical Support, but I have not seen an update which addresses this bug.

Purchase at your own risk.!

[BanjoBandit]

OK so that should explain y i cant play singleplayer... but does it effect comunity test chambers?

[Ultimatte]

Tried it now, game still crashes when playing ct chambers in co-op...

[Incryptx]

I was not attempting to solve the issue or offer a solution you should try, only summorizing the problem. It's a bug we cannot solve on the client side.

[Incryptx]

The ct co-op crash is a different bug and certianly a server side issue.

[SCL_Octorok]

CVScorp, how did you track the conflict/problem to those libraries?
If thats really the problem, then the DXupdate MSU must have cured it for me,
thanks.

-> from another post->
"yea, thats what i meant by "verified gamefiles", sry. I defragged my entire steam folder first, then verified cache, but got zero errors. Then i installed " Windows6.1-KB2670838-x64.msu ". then b4 rebooting, i reverted my NV gfx drivers back to 334.89 ( from 335.23 ).
Been playing Portal2 for 30 mins now w. no ctd's. not sure which or what fixed it, or if ive just been lucky for 30 mins, will continue to play through to see if it crashes any more, but it appears stable now.
*update-> still stable to point when acquire glados/potato."

[Incryptx]

Web Research. If you Google phrases like "STEAM PORTAL 2 SHAPERAPIDX9.DLL" and "STEAM PORTAL 2 FASTPROX.DLL" you will find threads associated with these files. I'm not taking credit for troubleshooting this problem, just reporting it. One thread in particular is from someone (credit due) who did track these files as culprits and filed bugs with STEAM.

I saw this thread unanswered and provided one.

[Incryptx]

Personally, I suspect it to be a DX problem, but only STEAM provides the DLL. The other is a known Windows WMI DLL and not the cause, as the same STEAM DLL is present in Portal (1) and this Portal game works, which brings me to the conclusion it could not be soley a DX problem, but that's my personal opinion.

[Incryptx]

Apparently, a STEAM/Portal 2 Update will solve the problem, but I have not seen one.