I'm still not quite sure I understand your use case .. or what 'custom task' you're performing.
I am creating a Custom Task that is associated with a VM object. I start the task and it says 'In Progress'. Then I delete the VM that the Custom Task is associated with and can no longer update the Custom Task
??? sounds like you're just deleting the VM ???
Again if you know which VM and no one else should have permission then you should use roles/permissions to not allow anyone else but you to delete or update.
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William Lam
VMware vExpert 2009
VMware ESX/ESXi scripts and resources at:
VMware Code Central - Scripts/Sample code for Developers and Administrators
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