What do I do when it's asking me for a county for my employment on Jan 1 2018 yet I can't put unemployed nor can I leave it blank to e-file it?

I'm trying to file my tax's electronically but it keeps coming up with an error in the federal section under what county did I start employment in January 1 2018 only I didn't start until April of 2018.  The error is that I left the slot blank and it won't let me e-file until I pick a county.  It won't let me put unemployed either.