Word web app cannot open the document due to an unknown error

​Recently I ran into an interesting error. This is related to SharePoint 2010 and Office Web Apps 2010. When opening any Word or PowerPoint documents SharePoint 2010 started throwing the following error.

“Word web app cannot open the document due to an unknown error. If the Problem persist try opening the file in Microsoft Word. ”

After searching around there were couple of articles which provided some help but I was not able to fix the issue.

http://sharepointknowledgebase.blogspot.ca/2011/09/word-web-app-cannot-open-this-document_05.html

http://technet.microsoft.com/en-us/library/hh269604(v=office.14).aspx

Since none of the above article helped I started looking into ULS logs and found few errors in there related to Office Web Apps.

w3wp.exe (0x0D6C) 0x0DD4 Office Web Apps Office Viewing Architecture b5es Monitorable Cannot create process for “C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\WebServices\PowerPoint\bin\Converter\AppServerHost.exe” /id 6c1f5a42-46c1-44b2-b919-100270bc58ad /convertingService net.pipe://127.0.0.1/09062522-2045-4126-8f60-13f56f0c8231 /assembly Microsoft.Office.Server.Powerpoint.Core.WebConversion.dll /type PowerPointServer.PowerPointServer /IsBatchedTracing True /LogQuota 10000 – err = 1314 
w3wp.exe (0x0D6C) 0x0DD4 Office Web Apps                Office Viewing Architecture    b10r Monitorable Failed to create the sandboxed process  

 

This led me to the following Microsoft Knowledge Base article.

http://support.microsoft.com/kb/2521084

I followed the instructions mentioned in the above article and it worked like a charm.

Resolution: Basically you will need Office Web Apps service account to have Replace a process level token on the local policy.

Just to save time for others I am going to post the steps here.

  • On the Windows 2008 server, select Start | Programs | Administrative Tools | Local Security Policy
  • Expand Local Policies | User Rights Assignment
  • In User Rights Assignment | Click on the Replace a process level token policy. Click on Add user or group. Type in the service account, resolve the name. Click OK. Click OK. Click apply. Click OK. (Below is a screenshot of the policy)
  • After the permission is set then launch a command prompt and type the following: gpupdate /force

Note: I need to reboot the server for this to work as after running gpupdate /force it did not work for me.