YAHOO.widget.Button

https://github.com/jenkinsci/jclouds-plugin/blob/76fc38812dd8289cab2b8dfeb41adf6e15aee830/src/main/resources/jenkins/plugins/jclouds/compute/JCloudsCloud/computerSet.jelly#L37

Can be fixed by applying the same change as in https://github.com/jenkinsci/ec2-plugin/pull/997

YAHOO.widget.Panel

https://github.com/jenkinsci/jclouds-plugin/blob/76fc38812dd8289cab2b8dfeb41adf6e15aee830/src/main/webapp/jclouds.js#L8

The  Panel can be replaced by a Jenkins dialog, see https://weekly.ci.jenkins.io/design-library/Dialogs/