The bug

In short, this bug is simply that the 'back' button on the multiplayer kick message screen can overlap with the kick message itself, if the message is approximately 9 lines or more. (Attached is a screenshot which shows this better).

How to reproduce

1. Start a server.
2. Set your GUI Scale to 3/auto.
3. Go into the console and run:

   /kick @s 541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541fffff451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff541f451f541f451ff154f1f541ffff
   

   → Text will appear behind the "Back" button. (Note: In newer versions the text appears in front of the "Back" button, which is not much better either.)