Downloaded the latest minimal ISO (antergos-minimal-2015.11.14-x86_64) and booted it.
First time I tried to install got this error. Rebooted and tried again. Still no luck.
Googled and found to try downloading latest cnchi from github, still same issue.
Next option said to run testing.sh, so did that and no luck again. Here’s the log: http://sprunge.us/XGMa
checking sha256sum for /install/var/cache/pacman/pkg/xorg-server-utils-7.6-4-any.pkg.tar.xz
returning error 33 from check_validity : invalid or corrupted package
edit: downloaded the full iso just now and tried that. Same issue.