I have exactly the same problem. Seems like Chrome 57 breaks with the old plugin API. The plugin is installed but not working. It worked fine in previous versions.
$ apt-cache policy flashplugin-installer flashplugin-installer: Installiert: 25.0.0.127ubuntu0.16.04.1 Installationskandidat: 25.0.0.127ubuntu0.16.04.1 Versionstabelle: *** 25.0.0.127ubuntu0.16.04.1 500 500 http://de.archive.ubuntu.com/ubuntu xenial-updates/multiverse amd64 Packages 500 http://security.ubuntu.com/ubuntu xenial-security/multiverse amd64 Packages 100 /var/lib/dpkg/status 11.2.202.616ubuntu1 500 500 http://de.archive.ubuntu.com/ubuntu xenial/multiverse amd64 Packages $ apt-cache policy chromium-browser chromium-browser: Installiert: 57.0.2987.98-0ubuntu0.16.04.1276 Installationskandidat: 57.0.2987.98-0ubuntu0.16.04.1276 Versionstabelle: *** 57.0.2987.98-0ubuntu0.16.04.1276 500 500 http://de.archive.ubuntu.com/ubuntu xenial-updates/universe amd64 Packages 500 http://security.ubuntu.com/ubuntu xenial-security/universe amd64 Packages 100 /var/lib/dpkg/status 49.0.2623.108-0ubuntu1.1233 500 500 http://de.archive.ubuntu.com/ubuntu xenial/universe amd64 Packages -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1680433 Title: Flash: This plugin is not supported. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/chromium-browser/+bug/1680433/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs