X_SHOT_KEY_INVALID
Means
a key chord the browser cannot press
Typical cause
an empty chord, a trailing +, a modifier other than Meta/Control/Alt/Shift (Ctrl is refused), one held twice, or a key that is neither one character nor a named key. Parsed before any key goes down, so no modifier is left held
Fix
spell it as modifiers then one key: Meta+K, Control+Enter, Shift+Tab, Escape