Below is the message I see in my mattermost.log
[2015/12/09 12:07:16 UTC] [EROR] /api/v1/admin/log_client:client code=500 rid=bp6ucq17t3rgfjunqu3xqs8d8w uid= ip=10.20.1.1 msg: Uncaught TypeError: Cannot read property 'page' of null row: 15 col: 21325 stack: TypeError: Cannot read property 'page' of null url: https://chat.mydomain.vm/static/js/bundle-4063.min.js [details: ]