When trying out mediawiki 1.33, i am seeing:
/w/load.php?lang=en&modules=startup&only=scripts&skin=timeless ConfigException from line 53 of /srv/mediawiki/w/includes/config/GlobalVarConfig.php: GlobalVarConfig::get: undefined option: 'EnableBlockNoticeStats'
#0 /srv/mediawiki/w/extensions/MobileFrontend/includes/MobileFrontend.hooks.php(428): GlobalVarConfig->get(string)
#1 /srv/mediawiki/w/extensions/MobileFrontend/includes/modules/ResourceLoaderFileModuleWithMFConfig.php(16): MobileFrontendHooks::getResourceLoaderMFConfigVars()
#2 /srv/mediawiki/w/includes/resourceloader/ResourceLoaderModule.php(727): MobileFrontend\ResourceLoaderModules\ResourceLoaderFileModuleWithMFConfig->getScript(ResourceLoaderContext)
#3 /srv/mediawiki/w/includes/resourceloader/ResourceLoaderModule.php(694): ResourceLoaderModule->buildContent(ResourceLoaderContext)
#4 /srv/mediawiki/w/includes/resourceloader/ResourceLoaderModule.php(830): ResourceLoaderModule->getModuleContent(ResourceLoaderContext)
#5 /srv/mediawiki/w/includes/resourceloader/ResourceLoaderStartUpModule.php(255): ResourceLoaderModule->getVersionHash(ResourceLoaderContext)
#6 /srv/mediawiki/w/includes/resourceloader/ResourceLoaderStartUpModule.php(438): ResourceLoaderStartUpModule->getModuleRegistrations(ResourceLoaderContext)
#7 /srv/mediawiki/w/includes/resourceloader/ResourceLoaderModule.php(727): ResourceLoaderStartUpModule->getScript(ResourceLoaderContext)
#8 /srv/mediawiki/w/includes/resourceloader/ResourceLoaderModule.php(694): ResourceLoaderModule->buildContent(ResourceLoaderContext)
#9 /srv/mediawiki/w/includes/resourceloader/ResourceLoaderModule.php(830): ResourceLoaderModule->getModuleContent(ResourceLoaderContext)
#10 /srv/mediawiki/w/includes/resourceloader/ResourceLoader.php(658): ResourceLoaderModule->getVersionHash(ResourceLoaderContext)
#11 [internal function]: ResourceLoader->{closure}(string)
#12 /srv/mediawiki/w/includes/resourceloader/ResourceLoader.php(670): array_map(Closure, array)
#13 /srv/mediawiki/w/includes/resourceloader/ResourceLoader.php(751): ResourceLoader->getCombinedVersion(ResourceLoaderContext, array)
#14 /srv/mediawiki/w/load.php(46): ResourceLoader->respond(ResourceLoaderContext)
#15 {main}In the logs, but in the js console i see "[6517215b23165c93329a295e] 2019-06-08 16:36:35: Fatal exception of type "ConfigException"".