Further to several posts about Raspberry Pi Digital Signage driving our office screens (https://tickett.wordpress.com/2014/12/03/anonymous-authentication-sql-server-reporting-services/), we recently restructured SQL Server Reporting Services. We updated the html/javascript file the Pi looks at (which redirects to SSRS) but it continued to try and use the old path.

This was fixed by SSH to the Pi then delete the browser cache;

pi@raspberrypi ~ $ cd /home/pi/.cache/chromium/Default/Cache/
pi@raspberrypi ~/.cache/chromium/Default/Cache $ rm -R *
pi@raspberrypi ~/.cache/chromium/Default/Cache $ sudo reboot