I can't delete keyframe in timeline and dope sheet I want to delete keyframe for rendering.
but a keyframe is there and i had only same picture.

It exists on the timeline. :(

I don't solve with "click the keyframe and ctrl+i" Strangely, the delete menu did not appear.

I don't solve whit "dope sheet" Strangely, the keyframe is not here!!!
Summary should be enabled as well as hidden objects.