Schedule E Worksheet (116 OAK LANE APT. 9) -- Disposition Worksheet (Copy 1): Line 4. Date Sold-1 must be entered, but I didn't sale any property. How do I correct that?

If you indicated in the Property Profile in the Rental section that you 'sold or disposed of this property' you will need to enter a Date (screenshot). 

If this is not correct, change your entry in Property Profile and also check your entry in Assets/Depreciation.

EDIT your property in this section and Continue to 'Tell us More about this Rental Asset' (screenshot).