In case you happen to run into this issue, we were attempting to install .net 3.5 for an application in Windows 2016 that required it.
So we ran the following command to install it:
DISM /Online /Enable-Feature /FeatureName:NetFx3 /All
It started out OK but then it got stuck for over 4 hours sitting at 49.4%.
Deciding to cancel the job, I tried to break it with a CTRL+C command.
Low and behold, the job skipped whatever it was hung up on, proceeded and successfully completed.
The application that required .net 3.5 worked like a charm.
Weird – but, whatever works! Hope this helps anyone out there.