Make sure you are not blocking content. [https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode Start Firefox in Safe Mode] {web link} A small dialog should appear. Click '''Start In Safe Mode''' (not Refresh). Is the problem still there? --------------- One issue that seems more common lately is Firefox's Tracking Protection feature. When it is blocking content in a page, a shield icon will appear at the left end of the address bar next to the padlock icon. This article has more info on managing this feature: [https://support.mozilla.org/en-US/kb/tracking-protection Tracking Protection] {web link} https://support.mozilla.org/en-US/kb/what-happened-tracking-protection?redirectlocale=en-US&redirectslug=tracking-protection https://support.mozilla.org/en-US/kb/content-blocking

This is likely because you are on Windows XP and do not have native support to play most media formats (e.g. MP4) via the HTML5 media player. If this worked before then they might have used a Flash based player.