Dont know if this can help you, but are you using a "path" directory and subdirectory structure for your files / assets?

I use external .txt files to save game data and i noticed that in development mode it all works fine, but when i tried to publish it returned an error but i dont remember which one right now.

I solved the problem moving the txt files to the root directory even with a path defined. I didnt understood very well the problem but i didnt spent too much time with it anyway.

Sorry for not helping you more.
Cheers.