Hi again Zack
It was a mistake to ask for the agent's logs, sorry for that (I thought converter was installed on a separate machine).
On more careful examination, the worker log contains:
2015-05-26T13:57:21.013+08:00 [03896 warning 'Default'] ERROR: Vmount library: Error 1450 while error communicating with the driver
-->
2015-05-26T13:57:21.029+08:00 [06228 warning 'Default'] ERROR 999 (loading hive) loading temporary hive \\.\vstor2-mntapi20-shared-2A3619CB00001000000000000A000000\\WINDOWS\system32\config\SYSTEM under key name mntApi356436467030447480.
Windows error 1450 means "Insufficient system resources exist to complete the requested service."
I don't know what this is caused by, there is something unusual on this source machine. You may eventually want to see http://stackoverflow.com/questions/19845580/system-error-1450-has-occurred-insufficient-system-resources-exist-to-complete
Regards,
Plamen