After some hours we managed to install wikidot.
The problem appears to be the first login
You have been inactive quite long while trying to log in and your session data have expired. Please try to click 'log in' once again.
We have checked in the php/actions/LoginAction.php and indeed the $seed is empty.
In the file php/screens/login/LoginIframeScreen.php
after the seed is added the command $runData->sessionGet("login_seed"); gives the right seed.