I did a upgrade from macOS el capitano to high sierra. After the upgrade, the inital login screen, where you enter your password, shows the icons of my profiles and then questionmarks instead of letters.
I can login and from that point everything is normal. If I lock the screen, the login screen is normal again, as usual.
What I did already to get rid of the error:
ontrestore default
and
sudo atsutil databases -remove
recommended form login screen characters all question marks login info isnt working.
Furhtermore I validated all fonts with via font book as noted here Suddenly my MacBook Pro (Running Sierra) has question marks ...
Nothing solved the problem.
Any hints?
The Problem seemd to be a permission issue. By solving another issue, I fixed thereby my login screen problem.
Checking /var/log/system.log I discovered the following line:
Aug 11 09:50:33 My-MBP softwareupdated[516]: libcoreservices: _dirhelper: 666: mkdir: path=/var/folders/zz/zyxvpxvq6csfxvn_n00000s0000068/C/softwareupdated/ modes[2]=0700: Permission denied
I did a chmod -R 777 /var/folders/zz and now it works. The questionmarks are gone and the login screen looks nice again.