MS has some (nonworking) advice for working around this issue here. In my experience, you can click "try again" until you're blue in the face, it will never work.
The real workaround that worked for me is found elsewhere, which is to enable the built-in administrator account and create a user account manually.
net user Administrator /active:yes
net user /add your_user_name your_password
net localgroup administrators user_name /add
cd %windir%\system32\oobe
msoobe.exe
Then poweroff. And finally disable the password-less admin account after installation (with net user Administrator /active:no).
My question is: why does the latter/real workaround work? Where exactly is the bug in the MS OOBE scripts?
By the way, I've only experienced it on single-core machines while installing 1809 LTSC. I did not experience it on VMs though (even single-core), as other people did, but only on real (and pretty slow) hardware.
