RTSP (Real Time Streaming Protocol) 403 is the error code for forbidden ie. the page you are trying to access is forbidden
Causes of the 403 error are as follows
A third-party program: download accelerator, firewall or anti-virus is preventing you from connecting to a particular site.
A windows update site control, which is usually installed on your computer, may be corrupt or is missing.
The system host file may be missing or not properly configured.
Files needed for Internet Explorer to work may be damaged or missing.
How you can fix the error 403
1. Disable any recently installed programs. The programs I am referring
to here are the programs mentioned above: accelerators, anti-virus
and/or firewall. You may want to disable each one individually and test
the page. If you disable all of them at once and it fixes the problem,
you won't be able to tell which one was causing the issue. But, by
disabling each one and testing you may be able to narrow down the
2. Reset Host file to default. If you develop websites and are
constantly updating this file, it's possible that you added settings
that is causing your current issue. A suggestion here is to reset the
host to it's original configuration. You may want to make a copy before
reverting to the original settings. You may want to refer to these
settings later or individually add them to the new host file. Follow
this Microsoft article, http://support.microsoft.com/kb/972034
and click the Fix Me option. This will set the host file back to it's default settings.