How to use Database Compare on 64-bit O365 ProPlus? RRS feed

  • Question

  • After getting all the prerequisites out of the way I finally got Database Compare to run. Only to have it throw another exception later:

    ERROR:Unable to cast COM object of type Microsoft.Office.Interop.Access.ApplicationClass’ to interface type ‘Microsoft.Office.Interop.Access._Application’”this operation failed because the QueryInterface call on the com component for interface with IID '' failed due to the followinf error:Error loading type library/DLL. (Exception from HRESULT: 0x80029C4A (TYPE_E_CANTLOADLIBRARY)).

    Research on this error suggests that it could be due to bitness mismatch somewhere. Everything on my system is 64-bit so now I'm wondering if the problem is that Database Compare itself is 32-bit and can't talk to my 64-bit database.

    Can anyone help me get past this error and get on with comparing files?


    OS: Windows 10 Pro 1909 18363.535 64-bit
    OFFICE: O365 ProPlus Version 1902 64-bit
    ACCESS: 16.0.11328.20492 64-bit

    Wednesday, December 18, 2019 11:49 PM

All replies

  • I could totally see how a 32-bit app cannot use 64-bit libraries to inspect a database.

    What I don't understand why your DC app is 32-bit. On my 64-bt-only machine, the app is in "C:\Program Files\Microsoft Office\root\client\AppVLP.exe", and that's a 64-bit location. Maybe you have more than one installed and are using the wrong one?

    -Tom. Microsoft Access MVP

    Thursday, December 19, 2019 5:10 AM
  • Tom,

       Your post offers an interesting clue. That is the place that the shortcut takes you when you click "Open File Location" but that EXE is"Microsoft Application Virtualization (MS App-V)". Which in turn calls the actual program. On my system it IS, in fact, pointing to DataBaseCompare.exe in the x86 folder.

    Here is the full path seen in the shortcut on 64-bit O365:

    "C:\Program Files\Microsoft Office\root\Client\AppVLP.exe" "C:\Program Files (x86)\Microsoft Office\Office16\DCF\DATABASECOMPARE.EXE"

    What's really confusing is that path doesn't exist on my system. If I run a search I can see that the true path to DATABASECOMPARE.EXE is a download folder that appears to be managed by App-V:

    "C:\Program Files\Microsoft Office\root\vfs\ProgramFilesX86\Microsoft Office\Office16\DCF"

    Notice the X86 in the path again. So App-V is downloading DatabaseCompare on the fly and it's downloading a 32-bit version for 64-bit systems.

    This appears to confirm my suspicions. What can be done? I need a 64-bit version of this application or ideally I need an application that can detect the bitness of my Access database and load it using the appropriate DLL.

    Thursday, December 19, 2019 4:42 PM