Getting an HTTP 503 Error After Upgrading a SSL Certificate and Restarting Your FogBugz On-Premise Instance



After upgrading the SSL Certificate and restarting your FogBugz On-Premise instance, you are getting an HTTP Service Unavailable 503 error when you try to access FogBugz. You have configured the FogBugz Application Pool identity to use a domain identity.


  1. Check which identity is used to start the application pool for FogBugz.
  2. Confirm that this identity used has the following rights that are required for FogBugz to work:

    • Adjust memory quotas for a process.
    • Allow log on locally
    • Log on as a batch job
    • Replace Process-level token

    If any of the above rights are not assigned to this identity, then you will need to assign these rights.
  3. If you are unable to assign the required rights to this identity, you can try to use the ApplicationPoolIdentity which is the default application pool identity and may have all of the required rights as the identity for the FogBugz Application Pool.


Once the FogBugz application pool identity has the required rights, FogBugz should start up and work as expected.