First some terminology has to be cleared up. I think you mean vSphere?? vCSA is vCenter Server Appliance, which manages ESXi hosts. But yes, if you are using vCenter (vCSA) then you cannot use the ESXi client. Just login to the vSphere web-client (Flash) or UI (HTML5) and make the changes. You should never use the ESXi client to make changes on a vCenter managed host unless the host has lost it’s connection to vCenter. This is because you risk it falling out of sync and losing the changes.
1.) What account are you using to login to vSphere? If it’s not Administrator@vSphere.local then this might be a simple permissions issue
2.) You haven’t provided us enough info here to help you. Please read this: Asking Better Questions
1 Spice up