As several users have seen this error, there is a new KB article describing a possible issue with Converter 3.0.3 and suggested workarounds:
http://kb.vmware.com/selfservice/microsites/search.do?cmd=displayKC&docType=kc&externalId=1006999&sl...
short url is:
http://kb.vmware.com/kb/1006999/
Cheers,EvilOne