Finally, I can play multiplayer and actually communicate at the same time.
A downloadable extension for Windows
What this is:
Sometime in 2018 (>1.4.1804 / >2.1.4), GameMaker runtime was updated to no longer poll gamepads when the window is not in focus. On one hand that is good, because you can switch between gamepad-controlled applications without accidentally throwing your character off a cliff, but sometimes you do want to poll gamepads while in background.
This little extension fixes that by convincing the game that the window always has focus (as far as gamepad logic is concerned).
How to use:
Call gamepad_force_focus() once. That's it.
If you for some reason need to disable the extension later, call gamepad_force_focus(false).
Based on this tweet by Russell Kay, this likely only works with XInput devices.
Click download now to get access to the following files: