When i click on the left side menu , it is not opening as expected

Hmm that's really interesting, looks like there aren't any elements selected, but that's what we usually see when there's an object selected, even then, there should be a back button, before the "Animate All", I think I'd duplicate this page, re-select and deselect an object (looks like there's only one there, Adobe logo), and see what's happening. Let's see if any other expert/user has any suggestions.