btw: I'm a developer of 8 years... not some amateur.

I just downloaded a fresh copy of 5.6.0.2 from the download page:
http://www.concrete5.org/download_file/-/view/44326/8497/...

I am running on a month-old vanilla (no customizations) version of WAMP. All of the requisites check out in the first step of the installation. The error happens in JavaScript method ccm_installRoutine10 - cannot read property "error" of null. The ajax request is made to the following url:

/concrete5/index.php/install/-/run_routine/standard/install_dashboard/

And the response is empty. I can see that other ajax responses contain a very short JSON response: {"error":false}.

Anyhow, I manually triggered ccm_installRoutine11() and made it through... and I just hope everything finished with the dashboards. Wanted to report this to you.