correct bug with None value

modules/toWizard.py

@@ -53,7 +53,7 @@ def check_end(val):
 
 def connect(data, text_mapping, i):
     target_idx = data['links'][i][1]  
-    if target_idx >= len(data['links']):
+    if target_idx==None or target_idx >= len(data['links']):
         error('There is an error with the Vizi file, care when you download it.')
         return None, None
     current_id = data['BPMN_id'][i]