I deinstalled it (including dependency) and installed it in main wiki (with all sub wikis option). Now it’s only working when triggered manually in URLNormalizerAdminSection not on save anymore.
But not sure if anything of those actions above had anything to do with this “magic”.
Btw: it seems that there is no translation key for “$escapetool.xml($propertyClass.translatedPrettyName)”. And it’s always setting back to “Default (Yes)” if chosing “Yes” or “No”. (Did this change in sub wiki.)
Thus it seems to indicate that $propertyClass is NULL which means that $configurationObject is NULL probably and that $configurationDocument is NULL and thus that there’s no URLNormalizer.Code.Configuration page in the wiki where you’re configuring the Admin UI.