Adding classic tween breaks animation and moves assets

[mat-z]

I am animating a bear in a walk sequence, and I am experiencing a peculiar problem. When I insert a classic tween between keyframes, the animation breaks and assets get moved around the stage at random. Please see the attached screenshots. First screenshot shows the animation before adding the tween. Second screenshot shows what happens when I try to insert a classic tween between keyframes. Oddly, I can add tweens between other keyframes in this animation with no problem (see screenshot 3), so the error seems completely random.

[kglad]

is there a reason you're not using the transform panel?

[Nicktendo28]

See if this video helps.

[Nicktendo28]

Try this tutorial. 

https://www.youtube.com/watch?v=tjE__KwrTIQ