Here's the complete warning/failure:
/sbin/ldconfig: relative path `1' used to build cache
warning: %postun(appstream-0.8.3-2.fc23.x86_64) scriptlet failed, exit status 1
Non-fatal POSTUN scriptlet failure in rpm package appstream
works fine here!
This update is force-installing a lot of gnome software on my KDE desktop. Even another file manager (nautilus). It should have never gotten to stable that way.
List of additional software required by the new update: