Under NVBU 10.x and early release of NVBU 11, when clicking on the "Create New" button for the "Use Target Set" field under the Secondary copy section of the Advanced Backup Options, the window that spawns is empty.
It is therefore impossible to create a new Target Set from the Secondary Copy section.
This is true for all supported web browsers and also affects the "Use Source Set" field.
Bug 26544 is set to be fixed in a future NV 11 Maintenance Release.
This issue is only observed when attempting to create new Target sets directly from the Secondary Copy window.
Creating a new Target Set works as intended from the "Create Backup Job" page. The set can then be saved and later chosen under the Secondary Copy section to replace an existing Target set.