SOLUTION: Facebook error – Invalid URL. The requested URL “/”, is invalid.

Two days ago a client of mine contacted me regarding problems accessing  Whenever the client attempted to access the site, he was met with the following error:

Invalid URL

The requested URL “/”, is invalid.

Reference #

Bizarrely, this only occurred when attempting to access, and never on any other websites.

Of course, the first thing I checked was his hosts file, which actually was completely empty/default.  Next, I flushed his DNS resolver cache with ipconfig /flushdns.  This also failed to solve the problem.

At this point, I began doing some research and found other users experiencing intermittent issues of the same sort across various internet forums.  The cause is unknown.  The solution, as it turns out, is easy: simply force the PC to resolve to the correct IP address and the problem is solved:

  1. Open the system’s hosts file.  Navigate to %windir%\system32\drivers\etc and open the hosts file using Notepad when prompted.
  2. Copy/paste the following line into the hosts file where the addresses are located:

That’s it–problem solved!