Many site issues can be caused by corrupt cookies or cache.

• Clear the Cache and

• Remove Cookies

Warning ! ! This will log you out of sites you're logged in to. You may also lose any settings for that website.

Type about:preferences<enter> in the address bar.

• Cookies; Select Privacy. Under History, select

Firefox will Use Custom Settings. Press the button on the right side called Show Cookies. Use the search bar to look for the site. Note; There may be more than one entry. Remove All of them.

• Cache; Select Advanced > Network.

[v57+] Select Privacy. Across from Cached Web Content, Press Clear Now.

If there is still a problem, Start Firefox in Safe Mode https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode

A small dialog should appear. Click Start In Safe Mode (not Refresh). Did this help?

While you are in safe mode;

Try disabling graphics hardware acceleration in Firefox. Since this feature was added to Firefox it has gradually improved but there are still a few glitches.

How to disable Hardware Acceleration {web link}

PLEASE help with this. I can't possibly be the only one experiencing this issue.

Did you follow the instructions in my last post?

Did you try Safe Mode?

I turned off hardware acceleration and that didn't fix the problem.

I've never had this problem before in Firefox, by the way.

This is the url for CNN live video. I continues to display only a thin horizontal video window, kind of like a letterboxing effect but with actual content being removed from the top and bottom:

http://go.cnn.com/?stream=cnn

Type about:support in the address bar and press Enter. Under the main banner, press the button; Copy Text To Clipboard.. Now in the Reply Box on the forum page, do a right-click in the box and select Paste.

This will show us your system details. No Personal Information Is Collected.

Maybe this is related to using a HiDPI (retina) screen with very large screen dimensions like your screenshot suggests.

If this only happening when a Flash player is used or also with a HTML5 media player?

It seems to be only happening when a Flash player is used in Firefox, but the CNN live video works perfectly well in Safari. I prefer to use Firefox and don't like switching browsers to view CNN and HBO video content. There must be a way to fix this within Firefox.

PLEASE HELP! Someone must have a solution. If it works on Safari, it should work on Firefox.