Where do I enter the 1099-S for sale of Time Share at a loss? Turbo Tax requires a Schedule E Worksheet but it doesn't apply.

Losses on Sale of Personal Use Timeshares are Not Deductible. So since you got a 1099-S you report it but set the cost equal to the selling price. The same as you would if you sold your personal residence at a loss and got a 1099-S

Losses on Sale of Timeshares Used as Rental Property May Be Deductible if: 

the timeshare qualifies as rental property then losses incurred on its sale are deductible. However, this is rarely possible. A timeshare will qualify as a rental property only if:

• it was rented at fair market value to unrelated parties for 15 days or more during the year, and
• its owners did not personally use it for more than 14 days per year or 10% of the total days rented, whichever is greater.

When determining the rental and personal use days for the 15-day, 14-day, and 10% cutoffs, you must include the combined use of all the owners of the timeshare unit. The result is that personal use by any owner of a timeshare is considered personal use by all of the owners.