What do I put when it says First date of employment during the current tax year is not a date in the current tax year. I put the day I started in 2014 but they say it’s wrong

If you are preparing your 2017 tax return, then 2017 is the "current tax year". 

Although you started your employment in August 2014, your first date of employment during the "current tax year" is January 1, 2017 (or 01/01/2017