Hi Suntrop
the argument at the end of the line (,"Mitglieder");) is where you specify the field you want this field to be placed above. If SS can't find that field then it just won't insert the field and I think in this case the actual field name is not translated (otherwise the whole DB structure would have to be translated too. So try changing your definitions to this:
Try removing it so your field defs look like this:
public function updateCMSFields(FieldSet &$fields) {
$fields->addFieldToTab("Root.Mitglieder", new CheckboxField("GoToAdmin", " Go to Admin area"), "Members");
$fields->addFieldToTab("Root.Mitglieder", new TreeDropdownField("LinkPageID", "Or select a Page to redirect to", "SiteTree"), "Members");
}
Hope that helps
Aram
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