Deductions & credits

It means that you need to prepare the NY return before the PA so that TurboTax can bring the actual NY tax liability over to the PA return for credit.  Based on your statement you did complete the state returns in that order.  

Step through the state return to be sure you didn't miss an entry where you can enter the gain for the NY return if your overall income is higher than indicated.  See the images below to enter your gain that is for the sale of your NY property.  Once this is completed, then go back through the PA return to see the credit.