It looks like the Jenkins Scriptler plugin is no longer available, due to security reasons: https://wiki.jenkins-ci.org/display/JENKINS/Scriptler+Plugin
"Distribution of This Plugin Has Been Suspended"
Is there a similar plugin that I could use to run saved Groovy scripts?
Hi you can store your groovy scripts in Managed Files and pass the parameters to groovy script through Extended Choice Parameters Plugin.
Or else you can download Scriptler plugin source code and add it to your /var/lib/jenkins/plugin folder and start Jenkins server. It will work fine.