There have been reports of similar problems with the slots table. Please add your experience to the ticket here:
https://phabricator.wikimedia.org/T224949
There is a patch up that should safeguard against my best guess at the cause of this. If you can provide additional insights as to exactly how this may happen, please do!
Thank you for your quick reply and for pointing me to the right direction. I am not sure if it's a mistake on my side, otherwise I'll gladly contribute.
I assume that the content_model id is lost/not generated somewhere between my clean MW install and the import of my templates via a script. I import pages using a custom maintenance script which reads a files' content from the file system and saves it to the mediawiki db using:
$title = Title::newFromText('Widget:MyWidget'); $wikiPage = new WikiPage( $title ); $newContent = ContentHandler::makeContent( $contentFromFile, $title ); $wikiPage->doEditContent( $newContent );
In the MW Class reference https://doc.wikimedia.org/mediawiki-core/master/php/classContentHandler.html#a2f403e52fb305523b0812f37de41622d it says "If [the modelId parameter for ContentHandler::makeContent() is] not provided, $title->getContentModel() is used." I assume, that it checks the namespace among others and uses javascript for Widgets? Because in my case it's a widget that causes the error. The extension is installed prior to the importation and the namespace 'Widget' exists.
Is there something wrong with the snippet?