I'm experiencing an issue during the major upgrade installation of April 2018 update on one of my desktop PC @work. I've got the same error during the "Fall Creators Update" six months ago fixed using the the Windows Update download tool executable. Still this error happens each time a major update is released and rolled out by MS on this PC using the Windows Update Module. No issue for patch Tuesday patch. We're on build 1709.16299.248 at the moment of writing (I'm referring to the 64bit OS on the stable channel)
Error code is 0x80242006.
What I've done before:
1. Running the Windows Update troubleshooter tool (it fixed a couple of minor problem but the issue persist)
2. Renaming the Download folder in the %systemroot%\SoftwareDistribution path to force Windows Update to rebuild its package database
At the moment I'm quite sure that running again the Windows Update download tool will start the update correctly but I really don't want to proceed that way.
Feel free to share with me other actions...i can share with you logs and registry keys eventually if needed.