I created poses for opened and closed book. But when I'm going to create a keyframe with (I - whole character) this error occurs:

I created poses for opened and closed book. But when I'm going to create a keyframe with (I - whole character) this error occurs:

If you look down at your time line you will see that the active keying set is "Button Keying..."
That is a custom keying set, you can see what is included in it in the scene tab of the properties window.
You can do one of two things.