The Wiki provided details related to downgrade is broken (issue 24380):
Start Jenkins ≥1.597.
Visit http://server/jenkins/JENKINS-24380/ and copy the unmigration instruction.
Shut down Jenkins completely.
Run the command as instructed by the step above.
Start Jenkins <1.597 with the same $JENKINS_HOME.
Here link http://server/jenkins/JENKINS-24380/ is not opening!
By the way, for most of the Jenkins users this is not a plugin issue, but Jenkins upgrade one.
The cause is that Jenkins 1.597 is not compatible with current version of the plugin and ticket
JENKINS-26508 Upgrade to 1.597 breaks Job page is not a duplication.