**Issue: **//HTTP Error 503. The service is unavailable// in IIS as shown in the picture below is caused if the application pool is paused or disabled.
Steps to resolve:
- Open IIS and look for the application pool of the selected website. here in this example the website name is test.
- Select the Application Pool as shown in the diagram below:
- Right click on the website name in the Application Pool and then click on Start as shown in the picture below:
- Browse the website and the error should be resolved.