What kind of bug is this?

Unity Engine
2

I could think of ten thousand ways that bug came up. Here’s a half dozen or so:

  • your input gathering is mis-mapped / misbinded to return ESCAPE when you hit Space-D

  • there is a script somewhere detecting that and going into pause mode
    → you wrote that script and forgot
    → someone else wrote it and forgot
    → it’s a script that has a bug and isn’t even supposed to do this

  • your keyboard (or its driver software) is bugged out and Space - D returns ESCAPE
    —> or your favorite Steam game shortcuts got accidentally left on

  • the os detects D-space as a shortcut to some function, takes focus away, your app goes into pause mode

  • unity itself contains some special shortcut key (unlikely but you never know!)

Pretty sure I’ve seen 100% of the above in some form or another.

Now start debugging to find out who brings up the pause menu!

  • how does it come up
  • who calls that method?

What is often happening in these cases is one of the following:

  • the code you think is executing is not actually executing at all
  • the code is executing far EARLIER or LATER than you think
  • the code is executing far LESS OFTEN than you think
  • the code is executing far MORE OFTEN than you think
  • the code is executing on another GameObject than you think it is

To help gain more insight into your problem, I recommend liberally sprinkling Debug.Log() statements through your code to display information in realtime.

Doing this should help you answer these types of questions:

  • is this code even running? which parts are running? how often does it run? what order does it run in?
  • what are the values of the variables involved? Are they initialized? Are the values reasonable?
  • are you meeting ALL the requirements to receive callbacks such as triggers / colliders (review the documentation)

Knowing this information will help you reason about the behavior you are seeing.

You can also put in Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene

You could also just display various important quantities in UI Text elements to watch them change as you play the game.

If you are running a mobile device you can also view the console output. Google for how on your particular mobile target.

Here’s an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong: