The sale is reported in the ASSET section of the rental prop entries ... did you ever depreciate the property ? If you did not then RUN to a local tax pro to get this error fixed since depreciation was REQUIRED and not an option.
I've had it since 2004 so it was depreciated in prior years taxes. I just don't know why I wasn't promoted to enter a sales price. I will amend when filed. Unless you have a different suggestion.
If you have already filed then once the original return has fully processed you can amend it. In the rental section review the assets being depreciated ... that is where you indicate the rental was sold. This would stop the depreciation being taken and prompt you for the sale price & costs of sale. If you have more than one asset for this rental then you need to prorate the costs appropriately.