Hi Josiean,

Sorry to hear Firefox is misbehaving!

You should be able to get Firefox out of full screen by moving your mouse up to the top-right of the screen until the menu bar appears. Click the icon that looks like a rectangle with two arrows in it.

Hope that does the trick!

You can toggle full screen mode on Mac via Command+Shift+F.

• https://support.mozilla.org/kb/how-to-use-full-screen

Josiean said

While I was in outlook (msn) the screen expanded and now everything is full screen. I cannot see either the toolbar or the dock or the bottom scroll bar and I don't know how to get back. I have to revert to old Safari in order to access my accounts.

This works. I had seen other replies that said to use the F11 button and that did not work. Since I have a Mac I tried command F11 and that did not work. It is the shift function that was missing, so thanks.