* Add param defaule value.

module/project/js/create.ui.js

@@ -93,3 +93,15 @@ window.waitDom('[name^=products]', function()
 {
     if($('.newProductBox').length > 0) productChange($('[name^=products]').eq(0));
 });
+
+window.productChange = function(e)
+{
+    let chosenProducts = 0;
+    $(".productsBox [name^='products']").each(function()
+    {
+        if($(e.target).val() > 0) chosenProducts ++;
+    });
+
+    if(chosenProducts > 1)  $('.stageByBox').removeClass('hidden');
+    if(chosenProducts <= 1) $('.stageByBox').addClass('hidden');
+}

module/project/model.php

@@ -1745,7 +1745,7 @@ class projectModel extends model
      * @access public
      * @return bool
      */
-    public function updateProducts(int $projectID, array $products = array(), object|array $postProductData): bool
+    public function updateProducts(int $projectID, array $products = array(), object|array $postProductData = array()): bool
     {
         $this->loadModel('user');
         $teams        = array_keys($this->getTeamMembers($projectID));

module/project/ui/common.field.php

@@ -71,6 +71,7 @@ $fields->field('productsBox')
 if($model == 'waterfall' || $model == 'waterfallplus')
 {
     $fields->field('stageBy')
+        ->className('stageByBox')
         ->control('radioListInline')
         ->labelHint($lang->project->stageByTips)
         ->label($lang->project->stageBy)

module/project/ui/create.html.php

@@ -60,6 +60,7 @@ formGridPanel
     on::change('[name=hasProduct]', 'changeType'),
     on::change('[name=future]', 'toggleBudget'),
     on::change('[name=begin], [name=end]', 'computeWorkDays'),
+    on::change('[name^=products]', 'productChange'),
     on::change('#parent, #budget', "checkBudget(0)"),
     set::title($lang->project->create),
     set::fullModeOrders(array('begin,days,PM,budget', !empty($config->setCode) ? 'parent,hasProduct,name,code,begin' : 'parent,name,hasProduct,begin')),