Hi,
First of all DP 7.x does not support VMware 5.5 so you should consider upgrading. If you don’t get this init phase done in 600 s (create snaps / resolve vms) so no Starting Backup for ... you will get this abort. It depends on the load on vCenter and how much this takes. I would suggest that you increase this timeout in global file.
Best regards,
Damir