iOS : Failed to load resource: The network connection was lost.

[chillin0531]

This problem occurs when loading static files(like .js or .css files) in iOS.
While debugging the web contents in Safari, the error 'Failed to load resource: The network connection was lost.' was presented on the console tab.
The same file URL loads without difficulty independently. When we try to load through js scripts, we get these errors.
What will be the reason of this type of failure?