When following the job dsl documentation for the Stash notifier plugin (https://jenkinsci.github.io/job-dsl-plugin/#path/job-publishers-stashNotifier) 

code:

job('blah') { publishers {  stashNotifier()  } } 

It produces the following XML:
<org.jenkinsci.plugins.stashNotifier.StashNotifier>
         <stashServerBaseUrl/>
         <stashUserName/>
         <stashUserPassword/>
         <ignoreUnverifiedSSLPeer>false</ignoreUnverifiedSSLPeer>
         <commitSha1/>
         <includeBuildNumberInKey>false</includeBuildNumberInKey>
</org.jenkinsci.plugins.stashNotifier.StashNotifier>
 
This triggers an "Unreadable Data" message:
      MissingFieldException: No field 'stashUserName' found in class 'org.jenkinsci.plugins.stashNotifier.StashNotifier', MissingFieldException: No field 'stashUserPassword' found in class 'org.jenkinsci.plugins.stashNotifier.StashNotifier'