the size of the clip when the test is faulty

It looks like on Windows Animate is filling the width and height of the screen, and you see the bars because the default scale mode is ShowAll. If you right-click on the test movie window you can change that to 100%, then resize your window to confirm that the content is the expected size.

You didn't ask about this, but from your file name it looks like you have had a lot of crashes. If you have a crash and use the recovered file, it may well be buried somewhere in the system. It might be better to open the recovery file if you need to, then save as to a more normal folder, with a new name.