Positioned Widget Causes Child To Disappear/Exception
As your log explains :
"constraints: BoxConstraints(0.0<=w<=Infinity, h=180.0)"
you have to define the width of the Container which is the parent of your Swiper. You have to also organize the items inside your stack which aren't positioned using rows and columns to keep its layout consistent across different screens.
add this line inside your Container :
width: MediaQuery.of(context).size.width,this will make your Swiper fill the screen width, you can modify it to any other value to suit your design.