The tag below your question indicates that you are using TurboTax Online. The What-If Worksheet is not included in TurboTax Online, and has never been included. It's only available in the CD/Download TurboTax software, and only in forms mode. TurboTax Online does not have forms mode.
If you have used the What-If Worksheet in the past, you must have used the CD/Download software, not TurboTax Online.
