In my drawable folder I have a few images and they all reference perfect, but when I try and add any more images with the exact same size in the same folder, and try to refe
It can be even more trivial than what the other posters suggested: if you have multiple projects make sure you did not create the xml layout file in the wrong project.
After creation, the file will open automatically so this might go unnoticed and you assume it is in the correct project. Obviously any references to drawables or other resources will be invalid.
And yes, I am that stupid. I'll close any unused projects from now on :)