When playing on any version older than 1.12.2 the entire PC "Softlocks" (the taskbar can still be brung up, the mouse still works but everything else is completely unresponsive) when ever any thing other than Minecraft is on the screen. This includes: notifications, taskbar, volume up/down indicator, Screen brightness, etc. As far as I know this only happens on Linux.

How To Recreate:

1. Launch any version of minecraft older than 1.12.2 on a linux device.

2. Click on volume up/down, screen brightness, or wait for a notification to appear, or try launching another app. (with minecraft running in the background)1

3. Watch as your PC becomes useless before your eyes!

The only way to make it go back to normal is manually hold the power button to restart.