The ADVL console leverages the VMware Vconverter software to perform the virtualization. The ADVL project provides a means to help automate the process of running the Vconverter.
Try running the Vconverter manually to perform a conversion. If you receive the same error, the problem is a native issue with Vconverter.
Please review the Vconverter logs and contact VMware for further assistance. To enable debug logging with the VMware components and for the location of the logs, please see the following KB article, specifically the sections about VMware logs:
https://support.quest.com/recovery-manager-for-ad-forest-edition/kb/155496
