Movie clip tweening

So I have been trying to get this to work for three days now and I am at the point that I feel like I must be missing something extremely obvious but I can't figure it out. I am trying to make a movie clip of a star getting larger and smaller just using a classic tween in a movie clip in order for it to continue throughout the rest of my animation. As you'll see in my video I copied an object to a new layer converted it to a graphic symbol and then converted it to a movie clip, then deleted the object from my new layer and brought the movie clip in to be sure that movie clip is the only thing on the layer. Then I double clicked the symbol twice to go into it make a new key frame scale it larger and then try to classic tween it and I get an alert telling me it is not a symbol. PLEASE if anyone can tell me what I'm doing wrong I would be extremely grateful! I have looked through quite a few topics that all seemed to be my same problem tried what the answers were as well as looked throguh Adobe Animate's youtube channel and nothing has fixed my issue.