Transaction

[Error Code: 1101] error caused by: 1 error occurred:
	* transaction invocation failed when executing transaction: [Error Code: 1101] cadence runtime error: Execution failed:
  --> a7746038cb034fe113043215ca1171ae21937a4a89fa80f19df27ae3f7d012b4:28:28
   |
28 |                             self.modifierRef.markAttendance(currentNFT: self.currentNFT, attendance: "true")    
   |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: unexpectedly found nil while forcing an Optional value
   --> 1e3c78c6d580273b.LNVCT:295:24