Solution
Go through the following troubleshooting steps to fix this issue:
1. Verify that the toolkit or library the VI is part of is correctly installed and activated by using the NI License Manager. If the toolkit does not show as activated proceed with licensing it by following the steps on the following article:
Activating NI Software Products.
2. If the toolkit the VI is part of is already licensed, check if there are any requirements for a specific development system. You can do this by doing a back search of the LabVIEW class and VIs in the LabVIEW Help Document. If a specific version of the development system is needed, activate it using the NI License Manager.

Figure 2: User Manual Requirements
3. If the issue persists after licensing the development system and the toolkit, try repairing or re-installing the toolkit.