Then you did not do what you said you did – you did not rename ‘reza1-mp4.axx’ to ‘reza1.mp4’.
You should never change the extension, but what you appeared to say was that you had – and then you have to change it back. That does not seem to be what has happened though, so it’s hard to help you out here.
But, there’s something strange still here. The file is now named “.mp4-vl2.axx” – where did ‘vl2’ come from!?