With any version of the scriplter plugin installed in a jenkins version greater than 2.442 or a java version past 11, the jenkins interface crashes with the log entry of:

org.apache.commons.jelly.JellyTagException: jar:file:/D:/Apps/Tomcat%209.0/webapps/jenkins/WEB-INF/lib/jenkins-core-2.452.3.jar!/hudson/model/ManageJenkinsAction/index.jelly:45:57: <st:include> Exception evaluating property 'size' for java.util.ArrayList, Reason: groovy.lang.MissingPropertyException: No such property: size for class: hudson.model.UpdateSite$Warning at org.apache.commons.jelly.impl.TagScript.handleException(TagScript.java:719)