The error is:
[2014-02-03 12:11:55.035 06472 error 'vmomi.soapStub[39]'] Resetting stub adapter for server TCP:192.168.14.25:9089 : service state request failed: class Vmacore::SystemException(The specified network name is no longer available. )
[2014-02-03 12:11:55.035 06472 warning 'vmomi.soapStub[39]'] Canceling invocation: server=TCP:192.168.14.25:9089, moref=vmodl.query.PropertyCollector:UfaPropertyCollector, method=waitForUpdates
[#6] [2014-02-03 12:12:16.037 03616 error 'task-3'] TaskImpl has failed with Vmacore::Exception: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
It seems the worker could not connect to the agent on the source machine. Check your firewall settings. For details have a look at the user guide about the ports used (p.25).
In general it is recommended to use the latest converter (5.5). It is also helpful to give more details when a problem arises - e.g. at what stage the conversion failed.
Regards