[UPD] remove group noone on user_id

views/calendar_views.xml

@@ -51,6 +51,9 @@
                     <field name="is_transfered"/>
                     <field name="is_attendee" invisible="1"/>
                 </field>
+                <page name="page_misc" position="attributes">
+                    <attribute name="groups"></attribute>
+                </page>
             </field>
         </record>