Why does my form say I lived in Washington for more than 366 days in 2016 when I stated I resided there from 01/01/2016 to 12/31/2016?

You likely visited the Sales Tax Deduction area in in the Federal return and the entries need review.  Visit "Deductions and Credits" -> "Estimates and Other Taxes Paid" -> "Sales Tax"

Most likely all of the entries total to more than 366 days (leap year) lived in a state or states.  Just double check the date ranges and ensure there is nothing overlapping.  Or delete the entries that are not relevant.