My dear sir ... you really need to get educated on the sale of rentals since you will not only have capital gains but recapturing of the depreciation as ordinary income. Seek local guidance and education or do some reading up yourself ... start with the IRS Publication 527.
If you have not been depreciating the properties then RUN to a local tax pro who is familiar with the form 3115 to get this error corrected on your next tax return.
