Hello there! I found a little problem with the WikiEditor toolbar. In my user preferences, I've activated the extended toolbar (german: "Erweiterte Bearbeiten-Werkzeugleiste aktivieren"), which works fine so far. As soon as I activate the Links&Table-assistants (german: "Assistenten zum Einfügen von Links und Tabellen sowie die Funktion „Suchen und Ersetzen“ aktivieren"), then, when I open the editor, the toolbar disappears.
Mediawiki: 1.27.4 Apache 2.4.29 PHP 7.2.10
The day before, I updated the server system software to Ubuntu 18.04. With the previously installed 14.04 and PHP 5.5, the toolbar assistant did work. I suspect the PHP version to cause the problem. Can anyone offer any hints, please?