2.12 Update Error - Call to undefined method Piwik\Updater::addComponentToCheck() (2 replies)

Hello,

I just update Piwik to 2.12.0 (automatic update).
And now, when trying to acces piwik, I have an Exception :

Fatal error: Call to undefined method Piwik\Updater::addComponentToCheck() in [...]/plugins/CoreUpdater/CoreUpdater.php on line 130
Fatal error: Uncaught exception 'Zend_Session_Exception' with message 'Session must be started before any output has been sent to the browser; output started in [...]/plugins/CoreUpdater/CoreUpdater.php/130' in [...]/libs/Zend/Session.php:443 
Stack trace: 
#0 [...]/libs/Zend/Session/Namespace.php(143): Zend_Session::start(true) 
#1 [...]/core/Session/SessionNamespace.php(34): Zend_Session_Namespace->__construct('CorePluginsAdmi...', false) 
#2 [...]/core/Nonce.php(39): Piwik\Session\SessionNamespace->__construct('CorePluginsAdmi...') 
#3 /[...]/plugins/CorePluginsAdmin/Controller.php(385): Piwik\Nonce::getNonce('CorePluginsAdmi...') 
#4 [internal function]: Piwik\Plugins\CorePluginsAdmin\Controller->safemode(Array) 
#5 [...]/core/FrontController.php(530): call_user_func_array(Array, Array in [...]/libs/Zend/Session.php on line 443

Any Idea ?
Should I / Can I continue the upgrade manually ?

Thanks,
Guillaume.