Can't submit test results to a private instance over API

I’m having problems while trying to set up a private instance of WebPagetest 2.13 to receive test results exclusively from API calls and display them. The idea is to integrate performance testing in our functional Cucumber-Selenium tests along the lines of GTAC 2013 talk “Web Performance Testing with WebDriver”.

So far, I have:

  1. Set up built-in Apache HTTP Server in OS X Mavericks.

  2. Installed WebPagetest 2.13: server-side (www/) only
    Just a side note, I had to add Options FollowSymLinks in Apache config under <Directory “/[skipped]/webpagetest”> because I was getting the following error in Apache logs on all URLs under webpagetest/:
    [error] [client ::1] Options FollowSymLinks or SymLinksIfOwnerMatch is off which implies that RewriteRule directive is forbidden

  3. Copied locations.ini.sample to locations.ini. locations.ini.sample has the “Test” location defined.

  4. Integrated API calls into sample test, based on Demo code for the GTAC 2013 talk “Web Performance Testing with WebDriver”

When test results are about to be submitted, I’m getting the following error:

WebPateTest test creation failed at http://localhost/runtest.php?location=Test& url=Test.testGoogleSearch&fvonly=1&f=json : {"statusCode":400,"statusText":"Error submitting url for testing"}

From what I understood, I don’t need to set up test agents in my case. Is it so and what might be the problem?