Software Updater won't run with PlayOnLinux

[David G Kinser]

Latest version Dell XPS 13 9360; Dell Dock WD15; 16.04.1; kernel version 4.4.0-59-generic.
Installed Arduino IDE, Kintracks, PlayOnLinux, Telegram Messinger
Software Updater hangs.
Ran sudo rm -rvf /var/lib/apt/lists/* and then sudo apt-get update.

Got message: W:The repository 'http://deb.playonlinux.com trusty Release' does not have a Release file., W:Data from such a repository can't be authenticated and is therefore potentially dangerous to use., W:See apt-secure(8) manpage for repository creation and user configuration details., E:Failed to fetch http://deb.playonlinux.com/dists/trusty/main/binary-amd64/Packages 503 Service Unavailable [IP: 51.254.83.230 80], E:Some index files failed to download. They have been ignored, or old ones used instead.

Unchecked PlayOnLinux in Software Updater-Settings-Other Software and Software Updater ran.
Uninstalled PlayOnLinux
Attempted to reinstall PlayOnLinux but it won't install