If broken it is, fix it you should

Using the powers of the debugger to solve the problems of the world - and a bag of chips    by Tess Ferrandez, ASP.NET Escalation Engineer (Microsoft)

New debugger extension for .NET (PSSCOR2)

New debugger extension for .NET (PSSCOR2)

  • Comments 19

Tom just blogged about a new debugger extension called PSSCor2, which is a superset to the SOS.dll extension that ships with the .net framework.

PSSCor2.dll has been around for quite some time at Microsoft, and pretty much everyone debugging .net code with windbg within Microsoft is using this since it contains all the goodness of sos.dll plus a lot of special methods for asp.net and other technologies running on top of the .net framework.  The news now is that after a lot of hard work by Tom and Jon Langdon in the CLR team, it is finally released publicly, YAY!!!

You can download it here and Tom promised to write some posts about the new commands so you might want to follow that… I will likely do the same later on as well…

Just to name two of the commands in there that I use a lot:

!dae  (Dumps out all the exceptions on the .net heaps with callstacks)

!aspxpages  (Dumps out all the asp.net pages that are currently executing or have been executing recently, along with the thread they are running on, what the timeout is and how long they have been running… excellent stuff)

Have a good one,


  • This is awesome. This would have been really useful about three days ago when I was trying to figure out some issues we were having with asp.net usercontrols and pages regenerating their class files unexpectedly.

    This has scored a permanent spot in my debugging toolbox.

  • I am having problem running the downloaded exe (psscor2.exe). It complains that it is not valid win32 app. Any ideas ?

  • This appears to be x64 version

  • It's almost sad how excited I am about this.

  • The installer seems to be 64bit, but it contains a 32bit, an IA64 and an amd65 (64bit) version of psscor...

    I'll check in with Tom to let him know about this, to see if they can make a 32-bit version of the installer available...

  • why not just provide a .zip....

  • I'm wondering about that too:)  will ask Tom,

    I really appreciate the feedback, please feel free to also comment on Toms blog about issues with the download package as he is more in the loop there, as far as being able to change something with it.

  • Thanks for making that extension public!

  • Thanks for making that extension public!

  • on x86 machines it's possible to extract the content with winrar, you've had to do it twice to get the x86 versión of the dll, I did it and use psscor2 without any problem, and I must say that it's a great extension.

  • "I will likely do the same later on as well…"

    waiting for your posts

  • This is great! It's unfortunate how badly the installer was botched.

    It's a 64-bit "installer" that when you run it, simply extracts a basic .zip file, which itself contains 3 versions of the DLL, for x86, 64bit, amd, etc. Whoa... how about just putting the .zip file up ;)

    Within 5 seconds of using this, we've narrowed down some problems!!!

  • The help file Jim Robbins posted is...helpful:


  • Amazing stuff.....have already started using new commands....really helpful.....Thanks a lot Tom and Jon.....

    And help file posted by Jim above is another piece of nice work....bravo guys.... :-)

    Just one thing, if Microsoft can throw some documentation, help for writing extensions.....I know many ppl have been waiting for this.....it would be really boost for debugging community.....


  • There should be a 32-bit installer now, thanks to all the feedback about this :)

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