I have three separate ayers that are gray instead of the usual blue/gold colors. On those layers, even though I am doing the same procedure, it gives me the start point and it then jumps to the end point without any motion on the way through. It also does not have a trail line. Another does nothing at all and the the third one has a solid line that is not workable. It also has a manner of deleting an image from a layer and then will not allow me to bring a replacement from the library..
What produces things like this and what do I do about them. What I did with the lost image was to delete the layer and start over again. That is not the way it should be handled. I haven't tried that method on the lack of motion ones yet. I would prefer to know what happens!
A general question is if it is possible to reverse an alpha tween so that it starts light and then goes to greater opacity? I think the images would look well shooting out of the fireworks display lightly and then gaining opacity.
How do I fix that?
Your three layers that are colored grey in the timeline have only one keyframe for each span of a single object. The blue layers indicate that you created motion tweens. The filled dot at the start and the filled diamond at the end are the two keyframes that contain the length of the animation.
Here's a good tutorial that explains how animating on the timeline can be accomplished: Animation Learning Guide for Flash: Timelines and keyframes | Adobe Developer Connection