Well now your environment and my environment is same . Im not facing this error with your src folder in app .
refer : http://prntscr.com/i59liw
I am running it on chrome ,can you please try this in chrome.
This error might be appearing because of access not control origin restriction set in browser .due to this image cache plugin is not able to download the image from external url and save it on machine .
Hence generating this js error .