ISP: N/A
Type of Internet Connection: N/A
Internet Connection Speed: N/A
Date & Time: All
Frequency: Always
Character Name: N/A
Race: N/A
World: N/A
Class/Level: N/A
Area and Coordinates: N/A
Party or Solo: N/A
NPC Name: N/A
Monster Name: N/A
In-Game Time: N/A
PC Specs: N/A

Steps:

1. Press Alt+F4 on PC while in the game
Expected result: Exit Game confirmation dialog box appears
Actual result: Nothing happens

Before patch 2.1 Alt+F4 would bring up the Exit Game confirmation dialog box. This is a standard Windows command to exit a program. I have triple-checked my keybinds, and Alt+F4 and F4 are not bound to any commands.