I copied a .m package file that I wrote on a Windows machine to my Mac running OSX 10.9. I can see the contents in a text editor and I can load it into a notebook and the functions run correctly. But if I attempt to open the file in the Mathematica editor the file shows up as blank. Has anyone else had this problem and, if so, how can I fix it? I can include the file if it will help.

Edit: Additional information

I initially transferred the file by mailing it from the Windows machine to the Mac. Today I decided to transfer it again using a thumb drive and this time the file contents show up in the editor so the problem is solved. But if anyone has an idea as to what caused the file to show blank in the editor I would be interested in the answer.