When trying to create a Collaboration Hub at https://en.wikipedia.beta.wmflabs.org/wiki/Special:CreateCollaborationHub, this happens:
[WNAl5gpEE4AAAFWGu8AAAAAK] [no req] BadMethodCallException from line 435 of /srv/mediawiki/php-master/extensions/CollaborationKit/includes/content/CollaborationHubContent.php: Call to a member function getContent() on a non-object (null) Backtrace: #0 /srv/mediawiki/php-master/extensions/CollaborationKit/includes/content/CollaborationHubContent.php(298): CollaborationHubContent->getMembersBlock(Title, ParserOptions, ParserOutput) #1 /srv/mediawiki/php-master/includes/content/AbstractContent.php(497): CollaborationHubContent->fillParserOutput(Title, NULL, ParserOptions, boolean, ParserOutput) #2 /srv/mediawiki/php-master/includes/page/WikiPage.php(2104): AbstractContent->getParserOutput(Title, NULL, ParserOptions) #3 /srv/mediawiki/php-master/extensions/SpamBlacklist/SpamBlacklistHooks.php(37): WikiPage->prepareContentForEdit(CollaborationHubContent) #4 /srv/mediawiki/php-master/includes/Hooks.php(186): SpamBlacklistHooks::filterMergedContent(RequestContext, CollaborationHubContent, Status, string, User, boolean) #5 /srv/mediawiki/php-master/includes/EditPage.php(1629): Hooks::run(string, array) #6 /srv/mediawiki/php-master/includes/EditPage.php(1921): EditPage->runPostMergeFilters(CollaborationHubContent, Status, User) #7 /srv/mediawiki/php-master/includes/EditPage.php(1470): EditPage->internalAttemptSave(NULL, boolean) #8 /srv/mediawiki/php-master/includes/api/ApiEditPage.php(396): EditPage->attemptSave(NULL) #9 /srv/mediawiki/php-master/includes/api/ApiMain.php(1543): ApiEditPage->execute() #10 /srv/mediawiki/php-master/includes/api/ApiMain.php(513): ApiMain->executeAction() #11 /srv/mediawiki/php-master/extensions/CollaborationKit/includes/content/CollaborationHubContentHandler.php(185): ApiMain->execute() #12 /srv/mediawiki/php-master/extensions/CollaborationKit/includes/SpecialCreateCollaborationHub.php(228): CollaborationHubContentHandler::edit(Title, string, string, string, string, string, array, string, RequestContext) #13 /srv/mediawiki/php-master/includes/htmlform/HTMLForm.php(663): SpecialCreateCollaborationHub->onSubmit(array, OOUIHTMLForm) #14 /srv/mediawiki/php-master/includes/htmlform/HTMLForm.php(555): HTMLForm->trySubmit() #15 /srv/mediawiki/php-master/includes/htmlform/HTMLForm.php(570): HTMLForm->tryAuthorizedSubmit() #16 /srv/mediawiki/php-master/includes/specialpage/FormSpecialPage.php(155): HTMLForm->show() #17 /srv/mediawiki/php-master/extensions/CollaborationKit/includes/SpecialCreateCollaborationHub.php(34): FormSpecialPage->execute(NULL) #18 /srv/mediawiki/php-master/includes/specialpage/SpecialPage.php(522): SpecialCreateCollaborationHub->execute(NULL) #19 /srv/mediawiki/php-master/includes/specialpage/SpecialPageFactory.php(576): SpecialPage->run(NULL) #20 /srv/mediawiki/php-master/includes/MediaWiki.php(285): SpecialPageFactory::executePath(Title, RequestContext) #21 /srv/mediawiki/php-master/includes/MediaWiki.php(860): MediaWiki->performRequest() #22 /srv/mediawiki/php-master/includes/MediaWiki.php(521): MediaWiki->main() #23 /srv/mediawiki/php-master/index.php(43): MediaWiki->run() #24 /srv/mediawiki/w/index.php(3): include(string) #25 {main}