Unable to Animate (Jump/Snap Problem)

Sorry I’m not really sure what to call this problem, I’ve been looking for anyone with the same problem but theres no posts about it anywhere.

I literally cannot animate in my scene anymore. If I open a new scene everything works fine however I need to fix the old one. I have attached a .blend showing the problem, the character is animated to move over 20 keyframes but instead will stay still for the first 19 then suddenly jump to the new pose. The same problem happens when I use shape keys, its really annoying me I dont want to have to set a pose for every single frame xD

Animation Problem .Blend - https://www.mediafire.com/?h6tn9sxv4nv1y2g

Link is dead, use dropbox or pasteall

Oh that was dropbox must have been on private or something, should work now thanks for letting me know!

Still nothing. You need to share the link, you can see it but no one else can.

Okay sorry it should be public now xD

Still dead.

wow okay I’ll just use mediafire, one moment thanks for helping!

All fixed hopefully

Select the rig in pose mode, open up a dope sheet window, there’s a menu, choose ‘key’ , interpolation mode, you have it on ‘constant’, you probably want linear or bezier. Change it and scrub the timeline.

Just for fun trydynamic effects ‘bounce.’

Thank you so much thats exactly what I was looking for!!