Ok, my problem seems to be similar to this, and this, but following the answers, there is not helping me. This might be because I am using Xcode 5, before I upgraded to this
I too had the same issue, the interesting thing was that I was already using the asset catalog when this happened. The solution that ended up working for me is described here: Invalid Image Path - No image found at the path. CFBundleIcons Xcode 5
Basically you need to add the image to the target you are building. To do that, select the image in the list of files under your project in the Navigation Pane, then show the Utilities Pane on the right and check the target under Target Membership in the Utilities Pane to the left