NetWorker: NMC failed to launch. Authentication is required.

The NetWorker Management Console (NMC) failed to launch. When attempting to open the application, a message appears, stating the proxy server requests authentication.
  

When you click "Cancel," it proceeds to display the NMC log in screen.

The NMC service is running on the NMC server:

• Linux: systemctl status gst
• Windows: sc query gstd

The NMC port (9000) is reachable from the host accessing the NMC:

• Linux: curl -v NMC_SERVER_ADDRESS:9000
• Windows (PowerShell): tnc NMC_SERVER_ADDRESS -p 9000

The NMC server can communicate with the AUTHC server: NetWorker: How To Identify Which Server is the Authentication Server Used By NMC and NWUI

The web browser on the host accessing the NMC is configured with Proxy settings.

Disable proxy setting in the browser.

Edge Browser:

1. Open Edge and click the three dots (menu) in the upper right corner.
2. Search "Proxy" then click Open proxy settings.
    
3. In the proxy settings, turn off Use a proxy server under Manual proxy setup.
4. Ensure Automatically detect settings is turned on.
    
5. Launch the NMC.

On Chrome Browser: 

1. Open Chrome. Click the three dots (...) in the upper right corner.
2. Search "Proxy" then click Open your computer's proxy settings.
    
3. Under Automatic proxy setup → turn Off Automatically detect settings (optional).
4. Under Manual proxy setup → turn Off Use a proxy server.
5. Click Save.

6.  Launch the NMC.