(Forgive me if I didn’t make myself clear. English is not my native language 
My setup:
Windows 10
NVIDIA RTX2060S
AMD R5 3600
How my game crashed:
The first thing I do when I play a freshly installed Halo game is to change the keybindings to the old CE style. Every time I reinstall MCC, I have to do it again. I can now change them really fast and MCC do responds to my requests swiftly.
However, when I do this in Infinite, the game seems having trouble dealing with my requests.
In this particular case, I was just launched a bot training session, then jumped to settings to rebind the keys. I rebound several keys successfully, but when I try to rebind Zoom to right mouse button, it says: Currently bound to _. Press _ to cancel. At this point, the settings menu stutters and freezes like it’s running something really heavy. Then after I clicked several other items in this menu, the game crashed.
Update after 10 minutes:
I tested this again, it seems I did something that made the “waiting for a new key” dialog hid in the background. It still accepts new input. I can even start a new change keybinding dialog. It just not showing on the screen. After I input a new key, for example, left mouse button, it will pop a new dialog that says bind conflict.
Update after 40 minutes:
When rebinding keys, if I click too fast, the game will not respond to my actions in time. For example, if I try to rebind a key immediately after I rebound a key, the new dialog will pop up after a severe delay. If I try this multiple times, at some point, the “Input New Key” dialog will have no images of keys on it. It will say Currently bound to <empty space> (Default is <empty space>) Press <empty space> to cancel. And the game will crash in a few more tries after this issue appears.