The other day I had a client contact me with an interesting SharePoint issue. Seemingly out of the blue, their SharePoint 2010 server CPU started being consumed by these two main processes with multiple instances:

  • SPUCWorkerProcessProxy.exe
  • conhost.exe

 When I looked into the issue, this is what I saw in task manager:

Runaway SPUCWorkerProcessProxy process

Whoa, that’s a lot of processes! 

And I saw the same thing for conhost.exe, which looked like this:

Runaway conhost process

So what are these processes and what do they do? I will spare you the long version and suffice to say they are related to Sandbox solutions. If you want the details, check out MSDN.

How to Fix the Issue in SharePoint

I suppose you could just stop the Sandbox service, however, there's a good chance you’re going to want to use Sandbox solutions at some point. So what else can you do?

I found a post on this issue on the forums that included a solution from Microsoft. It turns out to be a registry permissions issue. Check the following entries. The necessary permissions are specified for the local users group (SERVERNAME\Users):

  • HKLM\System\CurrentControlSet\Control\ComputerName\ActiveComputerName --> READ
  • HKLM\System\CurrentControlSet\Control\ComputerName\ComputerName --> READ
  • HKLM\System\CurrentControlSet\Control\Nls\Sorting\Versions --> READ
  • HKLM\Software\Policies\Microsoft\Windows\Safer\CodeIdentifiers --> QueryValue
  • HKLM\System\CurrentControlSet\Control\Session Manager --> QueryValue

In each case, the local Users group should have the listed permission. If not, add it. In my case (and others in the post), it was missing in the next to last key:

  • HKLM\Software\Policies\Microsoft\Windows\Safer\CodeIdentifiers


So let’s fix it. Click Add, and add the local Users group with the correct permission:

Query value registry permission

Now close the registry editor and open Central Administration. Go into Services on Server, and stop/start the Microsoft SharePoint Foundation Sandboxed Code Service. Now check out Task Manager:


I hope this post is helpful to other SharePoint users out there. If you have any questions about this entry or C5 Insight, please contact us.