Can't upgrade to macOS High Sierra 10.13.6

I did a restore of one of my machines to a Time Machine backup from July 1st (macOS High Sierra 10.13.5). The restore went fine but now want to update the mac to 10.13.6. The update downloads fine but after the restart and I get the Error 7e7aee96ca - the update can't be installed. Any idea what this could be? I saw another post for a previous version (10.13.4) but the suggestion to go through a full restore is not practical atm for me. Any idea