Moving to latest version of Jenkins means that there is a warning about Old Data to do with the Project Description Setter Plugin https://wiki.jenkins.io/display/JENKINS/Project+Description+Setter+Plugin .

 This is because it doesn't want to deserialise <charsetName>windows-1252</charsetName>.

 I now get the following error whenever a job runs with the Description Setter Plugin.

java.lang.IllegalArgumentException: Null charset name
at java.nio.charset.Charset.lookup(Unknown Source)
at java.nio.charset.Charset.forName(Unknown Source)
at org.jenkinsCi.plugins.projectDescriptionSetter.DescriptionSetterWrapper.readFile(DescriptionSetterWrapper.java:150)