Doktor plugin is affected by JEP-200 :

I use the step doktor and in the log there is this message :
java.util.concurrent.ExecutionException: java.lang.SecurityException: Rejected: kotlin.collections.EmptyList; see https://jenkins.io/redirect/class-filter/
and in catalina.out :

AVERTISSEMENT: org.jgrapht.DirectedGraph in file:/data/jenkins/plugins/build-flow-plugin/WEB-INF/lib/jgrapht-jdk1.5-0.7.3.jar might be dangerous, so rejecting; see https://jenkins.io/redirect/class-filter/
févr. 22, 2018 5:44:17 PM jenkins.security.ClassFilterImpl lambda$isBlacklisted$1
AVERTISSEMENT: kotlin.collections.EmptyList in file:/data/jenkins/plugins/doktor/WEB-INF/lib/kotlin-stdlib-1.1.51.jar might be dangerous, so rejecting; see https://jenkins.io/redirect/class-filter/