How to fix problem with full screen video on Youtube

If you are still getting this issue when you switch the YouTube video to fullscreen, (a) have Flash installed separately on your computer, and (b) Flash is updated to the latest version (currently 11.5.502.110), please try the following and let us know what happens:

Go to the chrome://plugins page. Click on the "+" sign at the top right of the page, to expand to see all Details.
1. Search for "Adobe Flash Player", and you will see all the plugins that you have for Flash. You will see 2 Flash plugins on your computer:
• ...PepperFlash\pepflashplayer.dll (which is bundled with Chrome)
• ...Flash\NPSWF32_11_5_502_110.dll (which was installed separately on your computer by you or an administrator)
Click the "Disable" link for PepperFlash
Relaunch Chrome (Chrome menu > Exit > restart Chrome)
Visit the YouTube video again, and switch it to full screen.
2. Let us know what happens.

To find out (a) above, go to your chrome://flash page. Do you see the Flash plugin for: ...NPSWF32_11_5_502_110.dll  ?

For (b), if the number "11_5_502_110" is different for you (11_4... or another lower number), it means that you do not have the latest Flash player. Please visit Adobe's Flash Player site here to get the latest update. This step will have to be performed in another browser, since the Adobe webpage will instead detect PepperFlash which is bundled with Chrome.