1. Most common mistake is when animated movieclip is placed in to the stage but it is aligned to the "stage background". Meaning that movieclip is aligned within "white background" (aka. stage).
- A quick fix is simply to set Position coordinates to X:0.0, Y:0.0.
2. If you set your movieclip coordinates properly but you get the result like in the image bellow: it happens when animated content inside movieclip is aligned to Position coordinates to X:0.0, Y:0.0. Important to note, content inside the movieclip can have any coordinates, but the movieclip in the main stage has to stay at Position coordinates to X:0.0, Y:0.0.
- To fix this issue open your movieclip and perform steps like in the image bellow.