Fix

booking.py

@@ -1324,8 +1324,8 @@ class UpdateHolderStart(ModelView):
             ('male', 'Male'),
             ('female', 'Female'),
         ], 'Sex', required=True)
-    phone = fields.Char('Phone', required=True)
     mobile = fields.Char('Mobile', required=True)
+    phone = fields.Char('Phone')
     email = fields.Char('Email')
     birthday = fields.Date('Birthday')
 

folio.py

@@ -210,7 +210,7 @@ class Folio(ModelSQL, ModelView):
     def check_out(cls, records):
         for record in records:
             cls.write([record], {'registration_state': 'check_out'})
-            cls.update_room(rec.room, 'dirty')
+            cls.update_room(record.room, 'dirty')
 
     @classmethod
     @ModelView.button