I've got the following PHP Fatal Error after upgrade from 1.9.0 to 1.9.1 :

Fatal error: Cannot access private property Statamic\Dipper\Dipper::$i in /.../_app/vendor/Statamic/Dipper/Dipper.php on line 138

My upgrade process is simply to replace old _app and admin folders and index.php and admin.php (since I noticed some changes in those files)

Thanks for your help !

Answered by Jason Varga! Go to answer.