With the (new) default configuration of Special:ContactPage, on core and extension head:
Notice: Undefined index: DisplayFormat in /var/wwwroot/wolfplex.be/www/w/extensions/ContactPage/ContactPage_body.php on line 204
[39b3a9ec] /wiki/Sp%C3%A9cial:Contact MWException from line 360 of /var/wwwroot/wolfplex.be/www/w/includes/htmlform/HTMLForm.php: Display format must be one of Array
(
[0] => table
[1] => div
[2] => raw
[3] => inline
)
Stacktrace:
```
#0 /var/wwwroot/wolfplex.be/www/w/includes/htmlform/HTMLForm.php(267): HTMLForm->setDisplayFormat(NULL)
#1 /var/wwwroot/wolfplex.be/www/w/extensions/ContactPage/ContactPage_body.php(206): HTMLForm::factory(NULL, array, RequestContext, string)
#2 /var/wwwroot/wolfplex.be/www/w/includes/specialpage/SpecialPage.php(384): SpecialContact->execute(NULL)
#3 /var/wwwroot/wolfplex.be/www/w/includes/specialpage/SpecialPageFactory.php(553): SpecialPage->run(NULL)
#4 /var/wwwroot/wolfplex.be/www/w/includes/MediaWiki.php(249): SpecialPageFactory::executePath(Title, RequestContext)
#5 /var/wwwroot/wolfplex.be/www/w/includes/MediaWiki.php(678): MediaWiki->performRequest()
#6 /var/wwwroot/wolfplex.be/www/w/includes/MediaWiki.php(475): MediaWiki->main()
#7 /var/wwwroot/wolfplex.be/www/w/index.php(41): MediaWiki->run()
#8 {main}
```