Transaction

[Error Code: 1101] error caused by: 1 error occurred:
	* transaction execute failed: [Error Code: 1101] cadence runtime error: Execution failed:
  --> 85c811ff506af191c5ddce6ed7669c8c4be46f22fcab89fa4c1d8c7bc186b7d7:12:46
   |
12 |                         self.transferToken <- collectionRef.withdraw(withdrawID: tokenID)
   |                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: unexpectedly found nil while forcing an Optional value
  --> 1c7d5d603d4010e4.Sharks:89:25
   |
89 |             let token <- self.ownedNFTs.remove(key: withdrawID)!
   |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^