Hi,
do you have the same issue as me from last few weeks/versions? I noticed that when I enter fullscreen mode i cannot close it. F11 button does not work.
The only solution is to close all cards, close all windows and then open Opera.

That is very annoying bug.
I am using Linux Mint 19.1 Tessa, Opera Developer 66.0.3480.0

@mishkigammi
@l33t4opera
@skpy

Hello guys.
I confirm, I have the same problem, also in Private mode. Nevermind if I press F11 or try contex-menu, window is only fast blinking and does not close fullscreen mode. Well, for me it looks like it try to return from fullscreen, but immediately returns to full.

@skpy
You have to close all tabs, then close Opera and start again - it will open not in fullscreen.

My configuration is:
Linux Mint 19.1 Tessa [Mate edition]
4.15.0-58-generic

@l33t4opera
Thanks, I will reply in that thread, it is better if more people report that issue.

@zalex108
I looked at Preferences file but I didn't find anything that can be related to that problem. But maybe I don't know what should I look for...

Shortcut is encrypted.

But many thanks for help. If you have any new idea for solution, do not hesitate to write it here, i will try it

@zalex108
Hi,
I tried your solution, I deleted file CurrentSession, launched Opera again and exiting fullscreen still does not work.
I switched on full screen both ways: by pressing F11 button and from context-menu and for both ways exiting is not possible.

@yanta
Hi,
thanks for the link to the thread. Unfortunately the solution provided by the intek13x does not work for me.

@sgunhouse

Thanks for a tip, but I also tried that, it does not work...
When I try to context menu or F11 button, the Opera's window is behaving strange, it blinks for a less than second and I can see it tries to change the size to normal, but then it again goes to fullscreen

Hi,
do you have the same issue as me from last few weeks/versions? I noticed that when I enter fullscreen mode i cannot close it. F11 button does not work.
The only solution is to close all cards, close all windows and then open Opera.

That is very annoying bug.
I am using Linux Mint 19.1 Tessa, Opera Developer 66.0.3480.0