I got this on testwiki after creating a new page:
[W4ajOQpAMFcAALGJkFIAAABJ] /w/index.php?title=Test-xxx&action=submit BadMethodCallException from line 311 of /srv/mediawiki/php-1.32.0-wmf.19/extensions/TwoColConflict/includes/InlineTwoColConflict/InlineTwoColConflictHelper.php: Call to a member function getUser() on a non-object (null) Backtrace: #0 /srv/mediawiki/php-1.32.0-wmf.19/extensions/TwoColConflict/includes/InlineTwoColConflict/InlineTwoColConflictHelper.php(159): TwoColConflict\InlineTwoColConflict\InlineTwoColConflictHelper->buildEditSummary() #1 /srv/mediawiki/php-1.32.0-wmf.19/extensions/TwoColConflict/includes/InlineTwoColConflict/InlineTwoColConflictHelper.php(115): TwoColConflict\InlineTwoColConflict\InlineTwoColConflictHelper->buildConflictPageChangesCol() #2 /srv/mediawiki/php-1.32.0-wmf.19/includes/EditPage.php(2901): TwoColConflict\InlineTwoColConflict\InlineTwoColConflictHelper->getEditFormHtmlBeforeContent() #3 /srv/mediawiki/php-1.32.0-wmf.19/includes/EditPage.php(702): EditPage->showEditForm() #4 /srv/mediawiki/php-1.32.0-wmf.19/includes/actions/EditAction.php(60): EditPage->edit() #5 /srv/mediawiki/php-1.32.0-wmf.19/includes/actions/SubmitAction.php(38): EditAction->show() #6 /srv/mediawiki/php-1.32.0-wmf.19/includes/MediaWiki.php(501): SubmitAction->show() #7 /srv/mediawiki/php-1.32.0-wmf.19/includes/MediaWiki.php(294): MediaWiki->performAction(Article, Title) #8 /srv/mediawiki/php-1.32.0-wmf.19/includes/MediaWiki.php(868): MediaWiki->performRequest() #9 /srv/mediawiki/php-1.32.0-wmf.19/includes/MediaWiki.php(525): MediaWiki->main() #10 /srv/mediawiki/php-1.32.0-wmf.19/index.php(42): MediaWiki->run() #11 /srv/mediawiki/w/index.php(3): include(string) #12 {main}