Checking for workflow processes

Fatal error: Call to a member function on a non-object in /home/httpd/vhosts/freecpd.se/httpdocs/kernel/classes/workflowtypes/event/ezapprove/ezapprovetype.php on line 177

Fatal error: eZ publish did not finish it's request
The execution of eZ publish was abruptly ended, the debug output is present below.

This happens when a content object is no longer avialable for the workflow. It might have gotten deleted.

I think there is a check for validity needed if this happens. If the workflow can't be executed properly for some reason we should delete it.

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[Update by Chen]
This bug also includes the fatal error issue in http://issues.ez.no/IssueView.php?Id=16949

PHP Fatal error: Call to a member function attribute() on a non-object in .. /kernel/content/ezcontentoperationcollection.php on line 258