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Updating to the RC caused an error
75637 FastCGI sent in stderr: "PHP Notice: Undefined index: allow_multiple in /var/www/EXAMPLE/piwik-1.2.5-rc2/core/Tracker/GoalManager.php on line 218"
Solution is to clear the tracker files on update, as the format of data might have changed (in this case we added a field in the goal)
(In ) Fixes #2269