Classic tweening will not occur on layers with ungrouped shapes, but I can't find offending objects

@Myra Ferguson @_keyframer @Nick Gioia 

I worked out what was the problem for this. 

There was a single keyframe at the end of a few of the layers that hand a tween applied to them.

I just had to remove these tweens and it exported perfectly without the error sign comming up.

That's a very misleading error message. Classic Tweens can't be applied to shapes whether they are grouped or ungrouped. Classic tweens can ONLY be applied to a symbol instance, one per layer, between keyframes. Follow these steps:

1. Draw something
2. Select it and convert it to a Symbol
3. Insert a keyframe further down the timeline on the same layer
4. Transform the Symbol's position, scale, rotaion, and or color effect on one of the keyframes
5. Apply a Classic tween

Result: You'll see the interpolation between keyframes when you play the timeline.

Have you made your objects into movie or graphic symbols? 

You shouldn't animate objects. 

You could try turning off the visibility of the other layers to seach that layer. It might also help to show that layer as outlines (click on the color rectangle to the right of the layer name) to help you see what's on it better.