Animated images rendering

Hello,

I am trying to make an animation of man walking.

I want to convert this animation as a PNG images compilation.

But when I click on this icon  :

,to convert as a images animation, my walking man is completely dismantled :

The weird thing is that when I convert the file (before converting it as a images animation) in .mp4 or .gif, it totally works !

Here is the animated GIF of the man walking :

Can you help me with this please ?

Thanks.