External exception C0000006 – Windows 2008 Terminal Server

With applications which start from a network share on a Windows 2008 Terminal Server , the error “External exception C0000006” can occur.
This is a known problem when multiple users start the same executable  from a network share.

To fixes this problem you need to add a reg setting.

Subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MRxSmb\Parameters

Entry: MultiUserEnabled
Value: 1

External exception C0000006


Programs that are run from a network share on Terminal Services close or generate errors

Problems when more than one user accesses the same file through Terminal Services

Posted in Windows 2008 R2 and tagged , , , .


  1. The Microsoft KB article says it applies to Windows 2000; are you sure it fixes the problem in Windows 2008 R2 too?

    Also, can this fix adversely affect the performance of the server?

  2. I had an application which gave me this error.
    After changing the REG key on my Windows 2008 R2 server, the problem disappeared.

    Later the software got an update for this problem to.
    That’s where the real problem was.

    It wil not affect the performance from the server!!!

    • Hi Arjan > can you tell me, what has been changed in the software?
      We have the same problem and I want to know, what has been changed in the software, so we can go back to the programmer.

      Thanks a lot for your Feedback

  3. Arjan did you move your app files from unc share to local filesytsem? This is very important info form me.

    • Eventually, yes.
      After a update from the software developer the app files were moved back to the UNC share.

      • Arjan, we are experiencing something very similar, Windows 2008 R2 Terminal Server, and running a application on a network drive. Can you please elaborate on what you actually did:
        did you set the RegEdit value, and move the files to a local file system? I would like to also know how the application was involved with this problem, what was fixed in the application to “solve” the C0000006 errors.

        • Deb,

          The first thing I did was setting the RegEdit value. This resulted in fewer exceptions, but the problem was still there.

          Then I moved the application from the UNC share to the local drive. This resolved the problem.

          The developers of the application released a new version with a fix for this problem. After installing the fix I moved the application back to the UNC share.

  4. Arjan, we too are experiencing something very similar, Windows 2008 R2 Terminal Server, and running a application on a network drive. You answered all the questions from Deb except the one on ‘what was fixed in the application to “solve” the C0000006 errors’. Any change you have answer to this question too?

    • Hi Rob,

      I’m sorry, but I have no idea how the developers fixed this problem.
      All I know is that multiple customers experienced the same problem.

      After a few weeks they provided an update for the software.

      • Hi Arjan,

        We had server2008 (non-R2) experiencing same problems. We lifted problem by assigning each user an unique share (all pointing to same directory). Now we are on Server2008 R2, without unique share per user. Problems are showing up again. We are contemplating: revert to unique share, moving application or asking SW-developers to look into it.

        What was the actual application you experienced problems with?
        Maybe you could ask the developers what they did to dissolve the problem.

        • The application with the problem was Caress from PinkRoccade.
          Unfortunately I don’t have contact with the developers anymore.

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