hide 'Folder' in the document-set properties, Content Type dropdown

Question

I have a document library where I use document sets. The setting 'Make "New Folder" command available?' is set to NO. When I however edit the properties of a document set, 'Folder' is available in the Content Type dropdown...

How can I hide 'Folder' in the Content Type dropdown? Is it a bug in document sets?

Answer 1

Look in the settings of the document library for the Folder content type, under the Content Types section.

Click on it and hit "delete" or "remove" (not sure exactly what the link says right now with no access to an SP environment)

Answer 2

I'm using following JavaScript attached to EditForm via JSLink property on Classic UI pages:

(function () {
    var OnPostRender = function (ctx) {
        if (ctx.ListSchema.Field[0].Name == "Title") {
            $(String.format("#WebPart{0}", ctx.FormUniqueId))
                .find("select[id$='_ContentTypeChoice']")
                .parents("tr:first")
                .hide()
            ;
        }
    }
    var ctx = {};
    ctx.OnPostRender = OnPostRender;
    SPClientTemplates.TemplateManager.RegisterTemplateOverrides(ctx);
})();

Or, open list with SharePoint Designer and remove Folder content type attached to the list

Or, use PowerShell for accessing the list and deleting Folder content type