See an error message in the reliability history (Win 10 Pro, 64-bit) saying:
Installation Failure: Windows failed to install the following update with error 0x80246007: Microsoft .Net Native Runtime Package 1.1.23101.0.
I've rebooted several times and also checked manually for this update but it's not being re-offered. Ran the Windows Update Troubleshooter and no issues reported.
BITS service is running (Automatic-Delayed Start).
Can't find anywhere to download the update for manual installation...