UE not reading exr,png and a load of other files

Hello everyone,
As I said in the title I’m having some troubles with exr, png, tiff, jpeg and basically evey file type which is not avi or mp4.

I’m using version 4.25.1 and i need to render some short sequences including an external video.
I converted the video into an exr sequence and then imported the sequence into the engine via File Media Source.
All ok till here but as i’m trying to play the sequence via the Media Player, the error you can see in the picture appears.
Same error occurs if using PNG and a load of other file types

Did anyone encounter this problem before? how did you solve it? It’s driving me crazy