Millisecond Forums

During license verification the client and server communicate via HTTPS. For that to work, the *client* must *at least* speak TLS 1.0 as HTTPS protocol version -- protocol versions below that, confusingly called SSLv2 and SSLv3, are not supported by the server any longer because they are outdated and insecure. The server will refuse to "speak" to that client and license verification will fail.

That's the technical background. Now, especially old and outdated Windows versions (e.g. XP) may not have TLS 1.0 (or above) enabled by default, although they can speak the protocol just fine (thanks, Microsoft). To enable TLS 1.0, direct your participant to go to

Internet Options -> Advanced -> scroll down to Security -> and check 'Use TLS 1.0'

on her/his computer. Once TLS is enabled, license verification should work.



In case TLS was already enabled on that machine, then something else on that computer or the network it resides in is blocking communication between the Inquisit engine on the client and the server (e.g. a local firewall or misconfigured Antivirus application, a firewall on the network perimeter).