Publication error with ScholarOne?
This happens with source files. For the .tex file that is OK: in fact, the .tex file should not appear in the proof. For the pictures, it probably means that ScholarOne doesn't process .png files: convert them to a supported file format, e.g. .pdf or .tiff.
In my experience, the above is usually enough to make the proof work, and if it's OK, submit, even if you still get that message for the .tex file.