can't view movie clip as background

I need to set a movie clip as background. Usually I have no problems, but now when I select my videoclip (.mp4), nothing appears, not even if I select it in the node editor or the movie clip editor.
If I do the same with another clip (also .mp4), this time the other movie is set as background.

I have no idea why blender doesn’t recognize the file, it’s basically the same just edited and exported from adobe after effects, but in the same format.

I really need to set this clip as background to render it out in a composite scene using nodes.
Someone knows what is the problem? thanks :slight_smile: