Sometimes when creating a wiki you get an error

Le wiki test a bien été créé mais certains documents nont pas été installés. Par conséquent, ce wiki peut avoir un fonctionnement défaillant. Vous devriez probablement le supprimer.

Starting job of type [wikiflavorjob] with identifier [wikiflavor/createandinstall/test]
Checking Hibernate mapping and updating schema if needed for wiki [test]
Exception thrown during job execution
class java.lang.NullPointerException: null
at org.xwiki.wiki.user.internal.DefaultWikiUserConfigurationHelper.saveConfiguration(DefaultWikiUserConfigurationHelper.java:124)
at org.xwiki.wiki.user.internal.DefaultWikiUserManager.setMembershipType(DefaultWikiUserManager.java:102)
at org.xwiki.contrib.wikiflavor.internal.steps.SaveWikiMetaDataStep.execute(SaveWikiMetaDataStep.java:91)
at org.xwiki.contrib.wikiflavor.internal.WikiFlavorJob.runInternal(WikiFlavorJob.java:75)
at org.xwiki.job.internal.AbstractJob.runInContext(AbstractJob.java:209)
at org.xwiki.job.internal.AbstractJob.run(AbstractJob.java:192)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Finished job of type [wikiflavorjob] with identifier [wikiflavor/createandinstall/test]