Pretty much as the subject says, the screensaver keeps activating and locking me out while I'm watching a long video, even while in full-screen. I've been able to find posts discussing this issue in Ubuntu or in earlier (non-LXQt) versions of Lubuntu, but I haven't seen it for 18.10+ yet (gnome-tweaks isn't going to help much here).
Is there any way to prevent this from happening?
(Edit: I had the wrong version listed initially; I'm still seeing the error in 19.04.)
Some programs are not really handling correctly the prevention of the screensaver, so I found really handy to use Caffeine whenever I was in trouble.
Can be easily installed as:
There is also an indicator included in the program(caffeine-indicator) so you can make it run on startup so that you have the indicator be displayed in the tray to enable it whenever you want