apps_vhost_plugin & socket with php5.6 or php7
Apps Vhost plugin, Line 172 - https://git.ispconfig.org/ispconfig/ispconfig3/blob/stable-3.1/server/plugins-available/apps_vhost_plugin.inc.php#L172
If the server runs php 5.6 or php 7, this section does not detect corectly if socket is used therefore all enabled apps will not work.