Unable to delete phantom disk (unused datastore files ) using the vco flow

Hi all,

Please help me as I am new to vCO and trying to delete phantom disks from datastores. The flow I am trying to run is Library > vCenter > Datastore and Files > Delete all unused datastore files. In the event description this is what I can see "TypeError: Cannot read property "keys" from null (Workflow:Delete all unused datastore files / delete files (item3)#2)". The vsphere version is 5.5.

Thanks