I had the same on my project.
I tried " super.setIntegerProperty("loadUrlTimeoutValue", 70000); " but to no avail.
I ensured all files were linked properly [ CSS, JS files etc ], validated the HTML using w3c validator [ http://validator.w3.org/#validate_by_upload ] , and cleaned the project [ Project -> Clean ]
It now loads and executes without the same error.
Hope this helps