This issue occurs due to the user account (Active Directory user or a Local User) does not have the appropriate permissions to log in to vCenter Server.
By default, the local administrators group on the vCenter Server is the only group that has access to the vCenter Server. If you try to log in as a user that is not a member of the administrators group (either directly or indirectly through another group), the log in fails because the user account has no permission to any object in the inventory.
Note: If vCenter Server is connected to your Active Directory domain, by default, the Domain Admin's group is a member of the Local Administrators group.