How can I replace the numbers correctly?

I am working on a patch, some national teams and the thing is that when I export the texture, change it the way I like and then try to import it won't show correctly. The numbers are nor visible, I see only this :


Could someone please explain me in a bit more detail how should I save the PNG file to make it work after I import it?

WHen I replace lakers with blazers for e.g. everything works fine, but when I try to import my own, I see those squares. How should I save the DDS or the PNG files to make this work?

The position is correct, because all i do is take the numbers change the color and send them back to the jersey iff file.

Nevermind I got it to work. You all were very helpful...NOT.