Cannot resolve Timeline in unity

Well I was trying something new with unity...so I started with timeline...and all the way its new...so will I was experimenting with timeline I changed a little bit setting, like i changed frames to seconds and then, I scroll to the timeline window, it seems zooming per seconds..but suddenly it changes to this(refer to pic)

and also when I press play it shows no movement...:(..I delete the timeline and then again open but it still showing me this...i restart my system but same issue...If anything you know..let me know it'll be really helpful...Thank You..:)