The iMac asked to update software so I said yes now I can't watch youtube or anything in full screen?

[iMore Question]

imac asked to update software so i said yes now cant watch youtube or anything in full screen?

no idea how i change this? anyone knows or has advice how to undo the update?
thank you soooo much

 

[phreddyl]

Re: imac asked to update software so i said yes now cant watch youtube or anything in full screen?

Can you manually pull the sides to make it full screen? What update did you install?