When accessing App Portal, the following error message may be displayed in the browser. This error appears when the web application is unavailable. The site is up and running, but the underlying application pools have an issue.

When this issue occurs, the error is present in multiple browsers for different users.

Solution

Check the Application Pools node in IIS

1. Open IIs and check the Application Pools node. The Application Pool is called SelfService. If it is stopped, an error message will appear when accessing the Web UI for the App Portal.
2. Start the application pool. If it fails to start, look at Windows event logs to see what errors are shown to guide your troubleshooting.

Errors occur most commonly when a specific account is used as the application pool identity and the username and/or password being used are incorrect. In this case, the event log will show the failed login attempts.

To correct this, follow the steps below to update the password for the Identity account in the Application Pool advanced settings and restart the application pool.

Update the password for the application pool identity

1. Open IIS.
2. Select the SelfService Application Pool.
3. Stop the Application Pool.
4. Select Advanced Settings in the right panel.
5. Expand Process Model and select the (...) for the Identity.
6. Select the Set… button to re-enter the correct credentials, including the domain and the password. Then select, OK.
7. Start the Application Pool and test the issue.
   
   

While the identity account is the most common cause of the application pool being stopped, it's not the only cause. If updating the password doesn't work, try restarting the application pool and investigating Windows event logs to find specific details on why it failed to start.