I know I qualify for a special refund ( 30% increase) on my property taxes, but for some reason Turbo Tax won't let me fill out the form. Does anyone know why?

Which state do you reside in?  

Minnesota

The Form M1PR will have to be filed by mail and not e-filed.   

You can return to the Form M1PR even if you have already filed your state return.  If you'd like to Print Form M1PR: 

1. Click on the add state return (you will not be adding a state, but this will open the return up for review)  
2. Continue to the Status of your state returns screen, then Revisit the Minnesota state return  
3. Get to the Let's Check for Minnesota Nontaxable Income screen and select Yes; I want to see if I qualify for these tax benefits
4. Click Continue until you arrive at the Other Forms You May Need screen. Confirm the Property Tax Refund (Form M1PR) box is checked, then Continue
5. Provide any information to complete the form 
6. Click Print Form M1PR. This will produce a final version of the form
7. Mail to the address provided on the screen

Note: Once you print the form, confirm that it is complete.

@k-4