univention-net-installer uses UCRV "repository/online/server" directly for "mirror/http/hostname", which no longer works as "https:// is included. We should introduce a new UCRV variable to make it configurable and default to updates.software-univention.de once Bug #41305 is fixed. If we do the later, "mirror/http/directory" must be updates as well as that path is not valid on u.s-u.de. Similar to Bug #45190 TEMPLATE still references UCS-4.1-0 and needs updating. FYI: auto=true with test-mode-install does not work with "debian-installer/locale=de_DE.UTF-8", as the text console is only 7-bit by default. On the hand USS breaks if "ISO-8859-1" is used, as than a comparison between UTF-8 and ISO-8859-1 fails. But "en_US.UTF-8" works and should be used as the default. FYI: UCS-4.2 still uses preseed_1.66 from Debian-Jessie. Only with 1.69 does the kernel command line arguments have a higher priority than the initramfs-preseed.cfg. With UCS-4.2 the preseed.cfg was moved from the initramfs to the /cdrom (or must be supplied via url= in PXE mode).
univention-net-installer provides /var/lib/univention-client-boot/preseed/TEMPLATE -> /usr/share/doc/univention-net-installer/examples/TEMPLATE, but it is compressed and thus named TEMPLATE.gz and dangling.
This issue has been filed against a component that was discontinued with UCS 4. Since UCS 4.4 is out of general maintenance this issue is now being closed. If this issue still occurs in newer UCS versions, please use "Clone this bug" or reopen it and update the UCS version. In this case please provide detailed information on how this issue is affecting you.