Geekspeak I don't understand

[Jon Ribbens]

On Tue, May 12, 2015 at 09:02:47PM +0100, Roland Perry wrote:
> Can anyone tell me what this really means, and what might have gone wrong,
> or what's amiss in 'my setup'?
> 
> "An error occurred during a connection to www.facebook.com. The server uses
> key pinning (HPKP) but no trusted certificate chain could be constructed
> that matches the pinset. Key pinning violations cannot be overridden. (Error
> code: mozilla_pkix_error_key_pinning_failure)
> 
>     The page you are trying to view cannot be shown because the
>     authenticity of the received data could not be verified.
> 
>     Please contact the website owners to inform them of this problem."

Is it a corporate computer or similar that might have a root
certificate installed by the IT department? The error message
means that the 'wrong' certificate was seen by your browser.
I assume if the certificate didn't verify at all then a more
usual error message would appear.