"+" key opens pause menu

Yup. Each time I press "+" (I use many mouse buttons that are keyboard shortcuts, and I use "+" key to activate/deactivate my laser pointer) the pause menu pops up. Just as when I press escape. Weird...

I'll just reprogram my mouse button for now, that's not a huge problem. Thought it was worth mentioning.

Locate ""***%LOCALAPPDATA%\Insurgency\Saved\SaveGames\Profile***" directory, and edit Controls.json file (use any text editor such as Notepad) and remove "ToggleMenu" entry for "key": "Add"

This should unbound the key so you cna rebind it in-game to your desired action.