Service Unavailable. HTTP Error 503. The service is unavailable.

Scenario

1. Launch Internet Explorer 11.0 or any other web browser.
2. Enter the URL for the Protect Server console: http://localhost/Protect or use its IP address http://<IP address>/Protect 
3. Notice the following error appears:

Resolution

1. Go to Control Panel - System and Security - Administrative Tools and launch Internet Information Services (IIS) Manager.
2. Under Connections expand the server tree and click Application Pools.
3. Ensure ProtectServer application pool is Started.

4. Launch again Internet Explorer 11.0 or any other web browser.
5. Enter the URL for the Protect Server console: http://localhost/Protect or use its IP address http://<IP address>/Protect

1. On the Protect server, navigate to C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\machine.config
2. Right click machine.config file > Properties > Security > Edit > Add > IIS_IUSRS
3. Go to Local Security Policy > Local Policies > User Rights Assignment.
4. Select Log on as a batch job policy, right click and select Properties
5. Ensure the logged in user to the Protect Server is part of this policy as well as the IIS_USERS group

Workaround