Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 0ac98617357aa58709ffe3e66ebe4ec4a47f9639f819dda8f7a075639da91844:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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