Hmm... it's not clear what's happens, could be a network drop:
2016-03-08T06:39:21.349+01:00 error vmware-converter-worker[54560] [Originator@6876 sub=task-4] VimConnectionHelper Keepalive to host 192.168.45.40 failed: vim.fault.NotAuthenticated
2016-03-08T06:39:21.350+01:00 error vmware-converter-worker[54560] [Originator@6876 sub=task-4] VimConnectionStore failed on keepalive for one connection
2016-03-08T06:39:21.350+01:00 info vmware-converter-worker[43744] [Originator@6876 sub=task-4] Reusing existing VIM connection to 192.168.45.40
2016-03-08T06:39:21.386+01:00 error vmware-converter-worker[43744] [Originator@6876 sub=task-4] managed to managed disk clone failed: vim.fault.NotAuthenticated
2016-03-08T06:39:21.388+01:00 error vmware-converter-worker[43744] [Originator@6876 sub=task-4] Disk clone failed with error vim.fault.NotAuthenticated
2016-03-08T06:39:21.389+01:00 error vmware-converter-worker[43744] [Originator@6876 sub=task-4] TaskImpl has failed with MethodFault::Exception: converter.fault.CloneFault
Could you try to turn off SSL from converter-worker.xml <nfc><useSsl> to false, then restart the service and try again?
HTH