Corporate or university firewalls sometimes block the NI License Manager from reaching the activation servers. If this occurs, use the "Activate via Web Browser" or "Activate via Email" options provided within the License Manager interface.
: Within the application, navigate to Help > About Multisim . The serial number is typically displayed in the top left of the "About" dialog box. ni multisim 143 serial number
Multisim Serial Number - NI Community - National Instruments Corporate or university firewalls sometimes block the NI