URI format in incorrect. Please see:
https://en.wikipedia.org/wiki/Uniform_Resource_Identifier[
^].
There are no cases when you have four '/'.
Besides, make sure your file is located under the root directory set up for your site. Normally, a Web application is executed in a sandboxed environment which won't allow access to any files beyond this directory.
Perhaps your best bet is to use relative path name, without URI scheme.
—SA