.NET Framework generates strange DCOM error

Question

Hello,

I am creating a simple application that enables merging of key-value pairs fields in a Word and/or Excel document. Until this day, the application has worked out just fine. I am using the latest version of .NET Framework 4.0 (since it provides a nice wrapper API for Interop). My sample merging method looks like this:

public byte[] ProcessWordDocument(string path, List<KeyValuePair<string, string>> kvs)
{
  logger.InfoFormat("ProcessWordDocument: path = {0}", path);
  var localWordapp = new Word.Application();
  localWordapp.Visible = false;
  Word.Document doc = null;
  try
  {
    doc = localWordapp.Documents.Open(path, ReadOnly: false);
    logger.Debug("Executing Find->Replace...");
    foreach (Word.Range r in doc.StoryRanges)
    {
      foreach (KeyValuePair<string, string> kv in kvs)
      {
        r.Find.Execute(Replace: Word.WdReplace.wdReplaceAll,
            FindText: kv.Key,
            ReplaceWith: kv.Value, Wrap: Word.WdFindWrap.wdFindContinue);
      }
    }
    logger.Debug("Done! Saving document and cleaning up");
    doc.Save();
    doc.Close();
    System.Runtime.InteropServices.Marshal.ReleaseComObject(doc);
    localWordapp.Quit();
    System.Runtime.InteropServices.Marshal.ReleaseComObject(localWordapp);
    logger.Debug("Done.");
    return System.IO.File.ReadAllBytes(path);
  }
  catch (Exception ex)
  {
    // Logging...
    // doc.Close();
    if (doc != null)
    {
      doc.Close();
      System.Runtime.InteropServices.Marshal.ReleaseComObject(doc);
    }
    localWordapp.Quit();
    System.Runtime.InteropServices.Marshal.ReleaseComObject(localWordapp);
    throw;
  }
}

The above C# snippet has worked all fine (compiled and deployed unto a Windows Server 2008 x64) with latest updates installed. But now, suddenly, I get the following strange error:

System.Runtime.InteropServices.COMException (0x80080005): Retrieving the COM class factory for component with CLSID {000209FF-0000-0000-C000-000000000046} failed due to the following error: 80080005 Server execution failed (Exception from HRESULT: 0x80080005 (CO_E_SERVER_EXEC_FAILURE)). at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck) at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache) at System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipVisibilityChecks, Boolean skipCheckThis, Boolean fillCache) at System.Activator.CreateInstance(Type type, Boolean nonPublic) at Meeho.Integration.OfficeHelper.ProcessWordDocument(String path, List`1 kvs) in C:\meeho\src\webservices\Meeho.Integration\OfficeHelper.cs:line 30 at Meeho.IntegrationService.ConvertDocument(Byte[] template, String ext, String[] fields, String[] values) in C:\meeho\src\webservices\MeehoService\IntegrationService.asmx.cs:line 49

-- I googled the COM error, but it returns nothing of particular value. I even gave the right permissions for the COM dll's using mmc -32, where I allocated the Word and Excel documents respectively and set the execution rights to the Administrator. I could not, however, locate the dll's by the exact COM CLSID given above. Very frustrating.

Please, please, please help me as the application is currently pulled out of production.

Anders

---

EDIT: output from the Windows event log: Faulting application name: WINWORD.EXE, version: 12.0.6514.5000, time stamp: 0x4a89d533 Faulting module name: unknown, version: 0.0.0.0, time stamp: 0x00000000 Exception code: 0xc0000005 Fault offset: 0x00000000 Faulting process id: 0x720 Faulting application start time: 0x01cac571c4f82a7b Faulting application path: C:\Program Files (x86)\Microsoft Office\Office12\WINWORD.EXE Faulting module path: unknown Report Id: 041dd5f9-3165-11df-b96a-0025643cefe6

- 1000 2 100 0x80000000000000 2963 Application meeho3 - WINWORD.EXE 12.0.6514.5000 4a89d533 unknown 0.0.0.0 00000000 c0000005 00000000 720 01cac571c4f82a7b C:\Program Files (x86)\Microsoft Office\Office12\WINWORD.EXE unknown 041dd5f9-3165-11df-b96a-0025643cefe6

Answer 1

Reinstalling Office 2007 Enterprise Ed. fixed the problem. But what a headache.