VSS to TFS ERROR: Retrieving the COM class factory error: 8007007e

I am trying to run an incremental migration using the VSS Upgrade tool. I'm migrating through the command prompt.

I have in the past successfully migrated all our projects and history to TFS, I have also checked in incremental migrations. However, now that I'm doing it for a 3rd time I get an error.

As far as I know nothing has changed. Any general tips in how I could go about debugging this would be helpful.

The error I get when running the vssupgrade migrate settings.xml command.

ERROR: Retrieving the COM class factory for component with CLSID {783CD4E4-9D54-11CF-B8EE-00608CC9A71F} failed due to the following error: 8007007e The specified module could not be found. (Exception from HRESULT: 0x8007007E)

Looking into the log file created by the analyze tool the error looks like this:

[VSS,             Error,     3, 2019/03/20 11:23:56.676] Exception: System.IO.FileNotFoundException
    Message: Retrieving the COM class factory for component with CLSID {783CD4E4-9D54-11CF-B8EE-00608CC9A71F} failed due to the following error: 8007007e The specified module could not be found. (Exception from HRESULT: 0x8007007E).
    Stack Trace:    at Microsoft.TeamFoundation.Admin.VssMigration.VssConverter.OpenVss(String sourceRepository, String passwd)
   at Microsoft.TeamFoundation.Admin.VssMigration.VssConverter.Initialize(ExecutionMode executionMode, MigrationSession migrationSession)
   at Microsoft.TeamFoundation.Admin.VssMigration.Api.MigrationSession.PrepareForProcessing(ExecutionMode executionMode, Boolean requireUserMapFile)
   at Microsoft.TeamFoundation.Admin.VssMigration.Api.MigrationSession.Migrate()
   at Microsoft.TeamFoundation.Admin.VssMigration.CommandLine.VSSUpgradeCommand.MainThread()
    Help Link: 
    BaseExceptionMessage: Retrieving the COM class factory for component with CLSID {783CD4E4-9D54-11CF-B8EE-00608CC9A71F} failed due to the following error: 8007007e The specified module could not be found. (Exception from HRESULT: 0x8007007E).

COM interop fails when the convertor runs under x64, the trick that may work is to start the conversion from a forced 32-bit command prompt, which you can start through:

c:\windows\SysWOW64\cmd.exe

That should give you a forced 32-bit context:

Another alternative is to change the corflags to force the convertor to x86 at all time:

corflags /32bit+ vssupgrade.exe