HTTP Error 503. The service is unavailable - Troubleshoot steps


HTTP Error 503

Troubleshooting steps

The error mentioned comes when there is no response from the server or server is down.

  1. Either the application pool identity ID password is incorrect / changed or
  2. the Database account password has expired / incorrect to which connection string is configured

Solution 1 : Verify the Application Pool details & reapply
Navigate to:
IIS -> Application Pool -> Advanced settings -> Identity -> Custom Account -> Set Credentials -> Provide Domain\Username & password.

Recycling option of the Application Pool (Right hand side option is available. )
Reboot the server.

How To : Domain\Username
Goto command prompt → whoami.

Below screenshot for reference.

Proceed to solution 2 if solution 1 didn’t resolve the issue.
Solution 2 : Verify if the SQL database password is active or expired by logging to the database with the credentials.
Once password is validated, reapply the password.

Solution Approach :

     Once done kindly follow the below approach to apply the settings in Orchestrator.
  1. Open IIS -> Orchestrator website -> Connection Strings

  2. Connection Strings (update the connection )


  1. Provide the server name , database name , username , password which is used to connect to the same database.



  1. Follow the same approach for both the connection string.
  2. Restart the website from IIS.
  3. If possible, reboot the server.

This will fix the issue. Now launch the Orchestrator

Note: The application pool users to the be included in IIS_IUSRS. (Computer Management -> Local users & Groups -> groups -> add the user)

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