For existing vSphere environments with the plug-in, you can upgrade the NetApp Element Plug-in for vCenter Server (VCP) using the latest management services package. There are additional complexities if you are upgrading as part of a vSphere upgrade or NetApp HCI or SolidFire full-system upgrade. You can also migrate settings from the Flash to the HTML5 version of vSphere Web Client if you intend to switch clients.
NetApp Documentation: Upgrade the Element Plug-in for vCenter Server
Switching from Flash-based to HTML5-based vSphere Web Client