The downloadable Windows Update troubleshooter might work better than the built-in one

I recently tried to get a Windows 10 1709 VM to update to 1803. It consistently failed about 78% into the first installation phase. The Windows Update troubleshooter from Settings | Update & Security | Troubleshoot didn't seem to change anything. The equivalent troubleshooter downloadable from Microsoft, however, did seem to have an effect. The update still failed for me, but at least it got noticeably further into the process. (I'm still trying to figure out what issue it's running into.)