I've also tried directly updating from the ISO files. I've tried running the DISM and SFC scans, they return no errors, disabling everything running in the background or on startup (including my antivirus software). I get a similar result with Windows Update Assistant, and the troubleshooter is useless. Windows update keeps trying to install 1803 - it gets about 70% of the way through then gives error 0x80070003 and says the update failed. I've been banging my head against the wall trying to update from 1709 to the newer feature updates, but they keep failing.
