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Possible workaround for Media Center guide download error code 20

Possible workaround for Media Center guide download error code 20

  • Comments 34

Our development team has found a possible root cause and workaround for error code 20 that may appear when trying to download television guide data in Media Center 2005.  The guide download error code article I previously published describes error code 20 as a file validation error, possibly caused by a mismatched guide package.  Previously, the only recommended workaround was to try downloading guide data again later.

We got a hold of a machine that was displaying error code 20, and the developer debugged and found the failure resulted from a call to a cryptographic API that is used to decode guide data (which is downloaded in an encrypted format).  For some reason we don't fully understand yet, this API returns a set of permissions that don't permit the guide data file to be opened correctly.

This workaround that we used to resolve this issue is the following:

  1. Log onto the computer as a user with Administrator privileges
  2. Close Media Center
  3. Navigate to the %ALLUSERSPROFILE%\Application Data\Microsoft\Crypto\RSA\MachineKeys folder
  4. Delete the file that starts with 1c93d682e65b0f3af0cd51385becba5e_
  5. Restart Media Center and try to download television guide data again

Error code 20 is being caused by one of the machine keys in that folder, but it appears to be a different key on each computer that hits this problem.

<update date="6/22/2006"> Updated this workaround so that it only includes deleting Media Center-specific RSA keys.  The previous workaround ended up deleting the entire RSA key store, which can impact other products on the system. </update>

 

  • Umm... wonder why it needs to access an RSA machine key. Are they watching you.
  • The Media Center guide download feature needs to access this key because it uses it as part of the process of decrypting the guide data that it downloads from the guide server. Data is stored on the guide server in an encrypted format because it is only intended for use by Windows Media Center.

  • Hi. I am still having problems downloading the guide. Everytime it tries to download, ehrec.exe would crashes. May be you can help out? Thanks
  • Hi Ti - Can you check and see if you have any files named *.crash in %windir%\ehome. Also can you check in eventvwr and see if you have any errors or warning in your Application event log? If possible, please send me the *.crash and an export of your Application event log so I can take a look? You can send them to aaronste@microsoft.com.
  • I have received error 23 a few times now, seems like since the Rollup 2 was released. I will reboot and then it will work fine.
  • Hi,

    I'm the CAPI1 owner. Aaron, I sent you an e-mail about this problem. Please answer the questions there to help me triage this problem.

    Thanks,
    Dan
  • Hi Aaron. I looked in the ehome folder but there is no such file that has .crash extension. I don't see any errors and warnings related to Media Center either. I do see the information logs from it mentioning about it managed to log suceessfully, when it is going to perform the next update, etc. The problem stills exist however...
  • Hi Dan - I received your email and I have contacted you regarding this issue. Thank you for your help!

    Hi Ti - could you try to download your guide data and let it crash again, and then choose to send the report to Microsoft. Then could you click the link that says View details of this report and send me the information that is listed there? That should allow us to go look at the crash information after it arrives on our server and hopefully that will help narrow this down. You can contact me using http://blogs.msdn.com/astebner/contact.aspx to send me this information.

  • Hi Eric

    In regards to your guide error code 23, that's a different issue than the one Aaron is describing in *this* blog entry. You might want to try the tips that he has provided at another blog entry.

    The link is available here
    http://blogs.msdn.com/astebner/archive/2005/11/10/491632.aspx
  • Hi Aaron,
    The thing is it does not give me Send Error Report dialog. Visual Studio Just-In-Time Debugger catches it and wants to debug. You can see the screenshot from my blog post...
  • Hi Ti - I'm not sure why it is not giving you a "send report to Microsoft" option in this scenario. Could you please gather the log files listed at http://blogs.msdn.com/astebner/archive/2005/10/16.aspx and send them to me so I can try to take a look?

    Also could you gather a list of the files and the version numbers for each of them for the files in %windir%\ehome on your system? Sometimes this type of crash is the result of mismatched binaries.

    You may want to try to uninstall and reinstall Update Rollup 2 to clear this up as well. You can uninstall by going to Add/Remove Programs, checking the Show Updates box at the top, then scrolling to the bottom and removing Hotfix for Windows XP Media Center Edition 2005 (KB908250) and Update Rollup 2 for Windows XP Media Center Edition 2005.

    Hopefully this will help...
  • Hi Aaron,
    I emailed you the logs info. I hope it would be figured out and solve the problem.

    Thanks,
    Ti
  • There's quite a few KB articles on permissions for the MachineKeys folder - could be related?
  • I get these repeated errors 20, too. Turns out it is the proxy from my firewall software. Once disabled the download worked.

    Any ideas what the connection is here...

  • Hi CaptainComic - There probably isn't any connection between the error you're seeing and the root cause I described in this blog post. Unfortunately, the same guide download error code can occur for multiple different reasons. We have seen other firewall issues with guide downloads in the past (for example the hardware firewall issue described at http://blogs.msdn.com/astebner/archive/2005/11/23/496503.aspx).

    I have added an additional suggested step to my blog post at http://blogs.msdn.com/astebner/archive/2005/11/01/487997.aspx to address AV/firewall/anti-spyware applications.

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