While migrating Windows vCenter Server 5.5 to VCSA 6.5u2c this error was observed and corrected using the following steps.
- Open Administrative Tools > Local Security Policy
- Navigate in the tree to Local Polices > User Rights Assignment
- Open the ‘Replace a process level token’ policy
- Add the migration user, in this case I added ‘Domain Admins’
- Click OK, there is no need to restart the server before re-attempting the migration
Related KB: https://kb.vmware.com/s/article/2148010