When getting a token from the security domain for a Dogtag 9 system, an attempt is made to reach the Representational State Transfer (REST) interfaces first. If it fails with a 404 error, the raised exception is tracked and an attempt to reach the old interfaces is made. This exception was changed from the deprecated ClientResponseFailure to a PKIException error. Prior to this update, this change was not reflected in the pki-core code. Consequently, it was impossible to upgrade an IPA server from Red Hat Enterprise Linux 6 to Red Hat Enterprise Linux 7. The code catching the exception has been modified accordingly, and the upgrade of the IPA server no longer fails.