From the log:
2015-04-08 20:17:58 mediawiki-vagrant wiki: [de39cffc] /w/api.php?action=flow&format=json&submodule=view-topiclist&vtlsortby=newest&vtllimit=50&vtltoconly=true&page=Talk%3AFlow_QA Flow\Exception\FlowException from line 90 of /vagrant/mediawiki/extensions/Flow/includes/Templating.php: Insufficient permissions to see userlinks for rev_id = sf12ccl14a5ruhad
#0 /vagrant/mediawiki/extensions/Flow/includes/Templating.php(174): Flow\Templating->getUserLinks()
#1 /vagrant/mediawiki/extensions/Flow/includes/Formatter/TocTopicListFormatter.php(56): Flow\Templating->getContent()
#2 /vagrant/mediawiki/extensions/Flow/includes/Block/TopicList.php(224): Flow\Formatter\TocTopicListFormatter->formatApi()
#3 /vagrant/mediawiki/extensions/Flow/includes/Api/ApiFlowBaseGet.php(33): Flow\Block\TopicListBlock->renderApi()
#4 /vagrant/mediawiki/extensions/Flow/includes/Api/ApiFlow.php(87): Flow\Api\ApiFlowBaseGet->execute()
#5 /vagrant/mediawiki/includes/api/ApiMain.php(1043): Flow\Api\ApiFlow->execute()
#6 /vagrant/mediawiki/includes/api/ApiMain.php(394): ApiMain->executeAction()
#7 /vagrant/mediawiki/includes/api/ApiMain.php(367): ApiMain->executeActionWithErrorHandling()
#8 /vagrant/mediawiki/api.php(90): ApiMain->execute()
#9 /var/www/w/api.php(5): include()