Could not load file or assembly Microsoft.Office.BusinessApplications.Fba VSTO error

Here is an error that plagued me (occasionally) for months.  Since Office 2013 was rolled out, we would sometimes get a call from a user trying to install an older Visual Studio Tools for Office add-in. Not sure how much of the specifics are at play here, but these were the facts in this situation:

Windows version: Windows 7
New Office version: Office 2013
VSTO Add-In version: Office 2007
VSTO Add-In application: Excel

The full text of the error was:

The value of the property 'type' cannot be parsed.  The error is: Could not load file or assembly 'Microsoft.Office.BusinessApplications.Fba, Version=, Culture=neutral, PublicKeyToken=71e9bce111e9r29c' or one of its dependencies. The system cannot find the file specified. (C:\Program Files (x86)\Common Files\Microsoft Shared\VSTO\10.0\VSTOInstaller.exe.Config line 10)


For months, all I could find was this post suggesting to repair Office.  Unfortunately, it failed to correct the issue and we were forced to uninstall and reinstall Office 2013 on a number of machines.  After a successful reinstall of Office, the VSTO installation ran to completion. This is a pain for both the support personnel and the users.

Today I found and successfully used the post at the end of this thread.  My experience wasn’t quite as clean as described, but it worked.  Here’s what I did:

  1. I right-clicked on setup.exe (installer for VSTO application) and chose ‘Run as administrator’. Answered [Yes] at the UAC prompt.
  2. I received a message informing that I already had the VSTO application installed.  The application was not showing in Excel, however this was already a step further than previous installation attempts.
  3. I pushed forward, found the VSTO application in Programs and Features and uninstalled it.
  4. Finally, I ran setup.exe again - this time not using ‘Run as administrator’.  It installed successfully and runs as expected. (Plan was to use Run as admin again if it failed, but it wasn’t required.)

Hope this helps others, too.