Why is it not possible for me to load a picture?

I really woundering why this error pops up when i am gonna load an image

21:03:05.979 - Image failed to load StarterGui.ScreenGui.Gems.ImageLabel.Image : rbxassetid://426509232 because Failed to resolve texture format

and the image just goes white why?

Because this is a decal, u must subtract 1 number from the end of it 426509232 so its 426509231, when subtracted if u get a place or shirt keep subtracting it till u get the image of it.