preventUnselect:true, 
 whether preventUnselect Boolean false can be selected when another node is not selected, 
 is set to true. Default is false 
 document:  https://my.oschina.net/u/3242.
  Hello, I have the same problem as you. Have you solved it? Please let 
 
 I also encountered the same problem, I am adding two events that will deselect the node to select again. 
 $(".tree"). Treeview ({
)
        data: FNodes, backColor: 'transparent', showBorder: false, color: "-sharpffffff", selectable: false, showCheckbox: false,
        onNodeSelected: function (event, data) {
            var sels = $('.tree').treeview('getSelected');
            for (var i = 0; i < sels.length; iPP) {
                if (sels[i].nodeId == data.nodeId) {
                    continue;
                }
                $('.tree').treeview('unselectNode', [sels[i].nodeId, { silent: true }]);
            }
            $(".tree").treeview('selectNode', [data.nodeId, { silent: true }]);
        },
        onNodeUnselected: function (event, data) {
            var sels = $('.tree').treeview('getSelected');
            for (var i = 0; i < sels.length; iPP) {
                if (sels[i].nodeId == data.nodeId) {
                    $(".tree").treeview('selectNode', [data.nodeId, { silent: true }]);
                    continue;
                }
                $('.tree').treeview('unselectNode', [sels[i].nodeId, { silent: true }]);
            }
        }
    });