https://forum.garudalinux.org/t/update-funktioniert-nicht/748/2?u=sgs
Edit
/etc/pacman.d/hooks/pamac.hook
Line 10 should look like this.
Exec = /bin/sh -c "zcat /usr/share/app-info/xmls/community.xml.gz | sed 's|<em>||g;s|<\/em>||g;' | gzip > "new.xml.gz" && cp new.xml.gz /usr/share/app-info/xmls/community.xml.gz && appstreamcli refresh-cache --force"