X Error of failed request: BadAccess (attempt to access private resource denied)

[QiangF]

error happens on running mousemode
https://github.com/randoragon/mousemode

This is the AI answer: The error indicates an X Window System client is attempting to access a resource (like a window, input device, or a specific property) without the necessary permissions, often because another client or the window manager already has exclusive access. Common Cause is Conflicting Window Managers/Clients: Another program, often a window manager, has already "grabbed" the resource (e.g., trying to register for substructure redirects or grab a specific key combination). This often happens with tiling window managers.