0 Argument 1 passed to CBLib\Session\SessionState::__construct() must implement interface CBLib\Session\SessionInterface, null given
I have exactly the same issue described in this topic, in the back end. And this is happening using the stable, new released Joomla 3.5 and PHP 7.0.4. In the front end, besides those issues from the back end, when I try to logout I have the following error : "0 - Failed to start the session: already started by PHP." and I have to refresh the page to come back to normal.
This is not because of Joomla 3.5 or PHP 7 and hopefully you will come up asap with an update as CB right now is useless (at least in the back end) where a lot of operations needs to be done to benefit from CB.
Also the fact the CB Login does not make use of Captcha in a native way, sooner or later I will have to give up in using CB.
However thank you for your efforts in trying to quickly keep up with all these errors.