MediaWiki internal error.

Original exception: [32f0209583225f94a83e3bee] /File:MKWSticker_29-15.png TypeError: MediaWiki\Parser\Sanitizer::removeHTMLcomments(): Argument #1 ($text) must be of type string, null given, called in /var/www/vhosts/wiki.gallery/httpdocs/1_43/extensions/DismissableSiteNotice/includes/Hooks.php on line 26
Backtrace:
from /var/www/vhosts/mariowiki.com/httpdocs/includes/parser/Sanitizer.php(389)
#0 /var/www/vhosts/wiki.gallery/httpdocs/1_43/extensions/DismissableSiteNotice/includes/Hooks.php(26): MediaWiki\Parser\Sanitizer::removeHTMLcomments()
#1 /var/www/vhosts/mariowiki.com/httpdocs/includes/HookContainer/HookContainer.php(159): MediaWiki\Extension\DismissableSiteNotice\Hooks->onSiteNoticeAfter()
#2 /var/www/vhosts/mariowiki.com/httpdocs/includes/HookContainer/HookRunner.php(3545): MediaWiki\HookContainer\HookContainer->run()
#3 /var/www/vhosts/mariowiki.com/httpdocs/includes/skins/Skin.php(1971): MediaWiki\HookContainer\HookRunner->onSiteNoticeAfter()
#4 /var/www/vhosts/wiki.gallery/httpdocs/1_43/PorpleExtrasAllWikis.php(531): Skin->getSiteNotice()
#5 /var/www/vhosts/mariowiki.com/httpdocs/includes/HookContainer/HookContainer.php(159): PorpleDismissedSiteNoticeNoCache()
#6 /var/www/vhosts/mariowiki.com/httpdocs/includes/HookContainer/HookRunner.php(2087): MediaWiki\HookContainer\HookContainer->run()
#7 /var/www/vhosts/mariowiki.com/httpdocs/includes/cache/HTMLFileCache.php(137): MediaWiki\HookContainer\HookRunner->onHTMLFileCache__useFileCache()
#8 /var/www/vhosts/mariowiki.com/httpdocs/includes/actions/ActionEntryPoint.php(122): HTMLFileCache::useFileCache()
#9 /var/www/vhosts/mariowiki.com/httpdocs/includes/MediaWikiEntryPoint.php(200): MediaWiki\Actions\ActionEntryPoint->execute()
#10 /var/www/vhosts/mariowiki.com/httpdocs/index.php(58): MediaWiki\MediaWikiEntryPoint->run()
#11 {main}

Exception caught inside exception handler: [32f0209583225f94a83e3bee] /File:MKWSticker_29-15.png TypeError: MediaWiki\Parser\Sanitizer::removeHTMLcomments(): Argument #1 ($text) must be of type string, null given, called in /var/www/vhosts/wiki.gallery/httpdocs/1_43/extensions/DismissableSiteNotice/includes/Hooks.php on line 26
Backtrace:
from /var/www/vhosts/mariowiki.com/httpdocs/includes/parser/Sanitizer.php(389)
#0 /var/www/vhosts/wiki.gallery/httpdocs/1_43/extensions/DismissableSiteNotice/includes/Hooks.php(26): MediaWiki\Parser\Sanitizer::removeHTMLcomments()
#1 /var/www/vhosts/mariowiki.com/httpdocs/includes/HookContainer/HookContainer.php(159): MediaWiki\Extension\DismissableSiteNotice\Hooks->onSiteNoticeAfter()
#2 /var/www/vhosts/mariowiki.com/httpdocs/includes/HookContainer/HookRunner.php(3545): MediaWiki\HookContainer\HookContainer->run()
#3 /var/www/vhosts/mariowiki.com/httpdocs/includes/skins/Skin.php(1971): MediaWiki\HookContainer\HookRunner->onSiteNoticeAfter()
#4 /var/www/vhosts/wiki.gallery/httpdocs/1_43/PorpleExtrasAllWikis.php(520): Skin->getSiteNotice()
#5 /var/www/vhosts/mariowiki.com/httpdocs/includes/HookContainer/HookContainer.php(159): PorpleFixDismissableSiteNotice()
#6 /var/www/vhosts/mariowiki.com/httpdocs/includes/HookContainer/HookRunner.php(983): MediaWiki\HookContainer\HookContainer->run()
#7 /var/www/vhosts/mariowiki.com/httpdocs/includes/Output/OutputPage.php(3186): MediaWiki\HookContainer\HookRunner->onBeforePageDisplay()
#8 /var/www/vhosts/mariowiki.com/httpdocs/includes/exception/MWExceptionRenderer.php(190): MediaWiki\Output\OutputPage->output()
#9 /var/www/vhosts/mariowiki.com/httpdocs/includes/exception/MWExceptionRenderer.php(109): MWExceptionRenderer::reportHTML()
#10 /var/www/vhosts/mariowiki.com/httpdocs/includes/exception/MWExceptionHandler.php(135): MWExceptionRenderer::output()
#11 /var/www/vhosts/mariowiki.com/httpdocs/includes/exception/MWExceptionHandler.php(239): MWExceptionHandler::report()
#12 /var/www/vhosts/mariowiki.com/httpdocs/includes/MediaWikiEntryPoint.php(222): MWExceptionHandler::handleException()
#13 /var/www/vhosts/mariowiki.com/httpdocs/includes/actions/ActionEntryPoint.php(83): MediaWiki\MediaWikiEntryPoint->handleTopLevelError()
#14 /var/www/vhosts/mariowiki.com/httpdocs/includes/MediaWikiEntryPoint.php(206): MediaWiki\Actions\ActionEntryPoint->handleTopLevelError()
#15 /var/www/vhosts/mariowiki.com/httpdocs/index.php(58): MediaWiki\MediaWikiEntryPoint->run()
#16 {main}