Error Code Troubleshooting
HTTP 500 error
You may also see errors in the Windows Event Viewer about "unable to activate".
Solution: There are multiple possibilities, but first ensure you have installed the ASP.NET Core Module/Hosting Bundle. If so, check the Windows Event Viewer for any of the messages below.
If you attempted to install the ASP.NET Core Module/Hosting Bundle before installing IIS on your server, you will need to re-run or "Repair" the installation afterwards.
503 Service Unavailable
Symptoms
Users receive a 503 Service Unavailable error when attempting to access Cortex.
Likely Cause
The IIS Application Pool used by Cortex has stopped.
This commonly occurs when the Application Pool identity is configured with a specific Windows account and that account's password has been changed or reset.
How to Check
- Open IIS Manager
- Navigate to Application Pools
- Locate the Application Pool used by Cortex
- Check the Status column
- If it shows Stopped, this is likely the issue
- Check the Identity column
- If it is set to a specific Windows account (not ApplicationPoolIdentity), verify that the password is correct
Resolution
If the Application Pool is stopped due to credential failure:
- Right-click the Application Pool
- Select Advanced Settings
- Under Process Model -> Identity, click the identity value
- Re-enter the correct password for the service account
- Start the Application Pool
After correcting the credentials, Cortex should become accessible again.