State 3 works for me in the C10.12799 IDE Properties by checking “Enabled” in “Value 3rd State” then you must enter a State 3 Value. Also entering STATE3(‘#’) in the Window… Editor is retained. if no Value is entered in the IDE or in STATE3() then it gets ignored and lost on close.
CHECK('Check State 3'),AT(396,91),USE(?CHECK1),STATE3('2')