Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 7e68b07ac84d0d5a4cc244030908f856ffcda9054537c4d0bc813643a472fc29:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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