Transaction

[Error Code: 1101] error caused by: 1 error occurred:
	* transaction execute failed: [Error Code: 1101] cadence runtime error: Execution failed:
  --> fb83808285aadbe5fe2198d195c86c3fa95493c567988b05c829e87576c52e56:36:10
   |
36 |           createListing(seller, storefront, request, paymentReceiver, nftRef, typeRef)
   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

  --> fb83808285aadbe5fe2198d195c86c3fa95493c567988b05c829e87576c52e56:66:2
   |
66 |   storefront.createListing(
67 |     nftProviderCapability: collectionCap,
68 |     paymentReceiver: paymentReceiver,
69 |     nftType: typeCache[r.nftTypeIdentifier]!,
70 |     nftID: r.nftID,
71 |     salePaymentVaultType: Type<@DapperUtilityCoin.Vault>(),
72 |     price: r.price,
73 |     customID: r.customID,
74 |     expiry: UInt64(getCurrentBlock().timestamp) + r.expiry,
75 |     buyer: r.buyerAddress
76 |   )
   |   ^

error: assertion failed: nft cannot be nil
   --> 3cdbb3d569211ff3.NFTStorefrontV2:619:4
    |
619 | 				assert(nftRef != nil, message: "nft cannot be nil")
    | 				^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^