Yellow border

[ripe escarp]

In most games, when I use the wand, a yellow line appears around the screen. This happened with Batman: Arkham Knight, but it stopped for some reason, and now it's happening with Assassin's Creed: Black Flag.
I took a screenshot but you can't see the yellow line.
In Batman, I applied the mod to the game menu and apparently that solved the problem, I did the same thing here, and it worked too, but I wanted to know why this happened.

[lean heron]

Which other games are you experiencing the yellow border on?

That yellow border is actually Windows 10's way of indicating that an app is recording your screen. You can get rid of it by disabling the Videos feature in the app settings!