Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 1b76dd7d5ea3c4037f64ad6e6111f3468e7983446e4aa411e2f7fb3b30310bb5:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

error: pre-condition failed: listing has already been purchased
   --> 4eb8a10cb9f87357.NFTStorefront:243:16