The message NoPermission appears during plug-in installation

To install, uninstall, or upgrade the NetBackup Web Client plug-in, the vCenter credentials require the Extension privileges. If your credentials do not have those privileges, the following message appears:

When you have set the Extension privileges for the credentials, click OK on the message and then click Register.

For instructions on setting the Extension privileges:

See vCenter privileges for managing NetBackup plug-in installation.