Hi,
I have found the solution by refering the latest version. I have to remove THIS.DOCK(1) from formlauncher.beforedock(), undock() which is used to prevent undock (I suppose).
Thank you for your helps.
Nice day
I am not the most powerful man in this world.
I am not the worst man in this world either.
I just as same as all of you.
I still need to learn from my mistakes...