Got your topology
That his error to occur by the following
1-This issue can Occur if we are using a remote SQL database with Windows authentication and the Update Manager service is Set to log on to the local system account.
Try the following
"NOTE: Make sure the vci-integrity.xml file, located at C:. \ Program Files \ VMware \ Infrastructure \ Update Manager, vCenter has the correct IP address If the IP address is incorrect, update it and restart the Update Manager service "
To change the service to the Windows NT login the same account que Has Been Given dbo permissions to the SQL database, please perform the instructions Following:
Login to vCenter System installed using RDP.
Click on Start, Run, Type Services.msc.
Locate and right click on VMware vCenter Update Manager Guest Agent and VMware vCenter Update Manager Service and then choose properties option (One service at the time) and then go to LogOn Tab.
Select the This Account option and then specify the SQL database administrator user name and password of the Appropriate SQL database administrator.
Click on Apply and OK.
Login to vCenter Server and then click on Plugins. From the Plug-In Manager console, right-click on installed VMware vCenterUpdate Manager and choose enable option.