lfe
While I do not know exactly what your settings looks like, I have also set a binding to a mouse movement (there should not be one in the default settings). If you want to fix things by hand, you can open up the Saves/lfe_keyboardshortcuts.json file in a text editor and remove the one that looks like a mess. You can also just delete that entire file if you want to have the settings be set back to the defaults.