Can you provide some more context here? What is your app trying to do? What is trying to read that file? Do you have a code sample that shows what is trying to load it and how?
Off the top of my head, I'd be inclined to agree that the path being used does not match up with the exact path to your file. You may want to `cf ssh` into your app container and see what the actual path is for your app. If your app is crashing and you can't get in via ssh, try to comment out parts of the app so that you can at least get something up and running where you can explore.
Hope that helps!