Filing as an Expat

I've been living overseas for almost five years and have filed taxes every year. I have always been able to file online with Turbo Tax, but this year it would not let me e-file. Nothing has changed for me. My salary is not much more than last year and is not enough to pay taxes on. I'm single and have no other deductions. I ended up printing, but to mail the papers is quite expensive from where I am. Looking for another solution.