Could be many reasons it hasn't sold.  Price is generally the first thing to look at.  Tired photos and poor marketing...make sure your photos are taken by a professional.  Maybe even have some drone aerial shots.  Have a staging consultant like myself come and take a look at interior (and exterior if needed) condition, staging, what can we do to give it the "WOW factor and make it "POP?"  We need to make it appeal to the buyers!  Depersonalizing can be a big help!  These are some great places to start.