Hi does your ePO 4.5 patch meets the upgrade requirements ?
How do i check wether the patches meeting the requirements
Please review the 'Installation requirements and recommendations' section of the ePolicy Orchestrator 4.6 Installation Guide.
If you don't have a copy you can find it on the McAfee Service Portal site:
The commonest mistakes are attempting upgrade when still using IE6 or Sql2000. Neither of which are supported by ePO 4.6