Reverse the check for http response code.
There are many codes other than '404' which indicate that the media file is not present or otherwise unusable. Instead of checking for a particular failure mode, check for explicit success. I ran into this on a server that had directory listing disabled, and returned a 403 (access denied) error on non-existant files.
… shown in the list
…ith the chrome warning popup
fixed bug 1716 - fixed an index out of bounds exception in repeatChatMessage
Related to issue #1710
Support pdf extension in uppercase https://code.google.com/p/bigbluebutton/issues/detail?id=1711
Re-enabling the common shortcut keys to change the slides