Transaction

[Error Code: 1101] error caused by: 1 error occurred:
	* transaction execute failed: [Error Code: 1101] cadence runtime error: Execution failed:
error: unexpectedly found nil while forcing an Optional value
   --> 449039c7e972131436b5bd6747a09f248cb17a7dc0a42e2a9a03af212cbab07f:120:18
    |
120 |         let nft = collection.borrowPack(id: saleItemID)!
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^