Unable to cast COM object of type

If you receive an error similar to the message below, it could be due to having multiple versions of Microsoft Office or Visio registered on your system, but only a single version actually installed.

For example, you have Word 2013 installed but previously had Word 2010. Word 2010 has been uninstalled but some registry keys have remained. 


Unable to cast COM object of type 'Microsoft.Office.Interop.Word.ApplicationClass' to interface type 'Microsoft.Office.Interop.Word._Application'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{00020970-0000-0000-C000-000000000046}' failed due to the following error: Library not registered. (Exception from HRESULT: 0x8002801D (TYPE_E_LIBNOTREGISTERED)).

This can affect Visio, Excel, PowerPoint and Word. The error could occur when logging in to iServer or via an interaction with Office or Visio, such as the creation of a document or export of data.

There are two possible solutions for this:


  • Delete the problem key(s) from the registry. Please submit a support request for assistance with this. Before altering the registry you should always make a backup of the keys you are working with. See this article: https://support.microsoft.com/en-us/kb/322756

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