The error message about undefined \aclabelfont
is independent from package scrlayer-scrpage
. I do not known, which package needs it but redefines it instead of defining it (acronym
, e.g., would need but also define it). Maybe you are using a not well defined template.
Nevertheless, as you can see from the CTAN Catalogue entry of scrlayer-scrpage
the package is part of the KOMA-Script bundle. You should not try to download and install scrlayer-scrpage.sty
without a complete KOMA-Script installation, because the package depends on other parts of KOMA-Script, e.g., package scrkbase
, scrbase
, scrlayer
.
The link above also documents that MiKTeX and TeX Live knows KOMA-Script as package koma-script
. So you can and should simply use the package manager of your TeX distribution to install it. Experienced users can also use KOMA's package repositories to install a current pre-release of KOMA-Script or to download a TDS-archive. The TDS-archive of the current official release is also available from CTAN.
koma-script
and is part of standard distributions.