OK does not tax out-of-state long-term capital gains. However, turbo tax insisted on completing an OK Form 561 which the state says I do not need. The problem is that the form has a 'type property sold' menu (line 3) and even though the form shows 0 for OK capital gains you cannot move forward without selecting from one of the 6 choices none of which apply.
Turbo Tax needs to check the interface between the Federal and OK tax forms. If the capital gains shown in Schedule D are not from OK then skip completing OK Form 561.