Secure connection failed: the authenticity of the received data could not be verified

[Fli]

Firefox:
Secure connection failed - The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
Chyba zabezpečeného spojení - Požadovanou stránku nelze zobrazit, protože nelze ověřit autenticitu přijatých dat.

Chrome:
ERR_SPDY_PROTOCOL_ERROR

SOLUTIONS? MAYBE:

-> tried to flush sockets at chrome://net-internals/#sockets
-> tried to reconnenct VPN server
-> tried doing "ipconfig /release" then "ipconfig /renew" at the command line (Windows, Run, "cmd").

[RuskinF]

The best answer to this problem is to update the browsers to the latest versions.
This ought to solve the issue.
If that does not work then you should uninstall the browsers and reinstall the latest versions of these browsers.