Transaction

[Error Code: 1101] error caused by: 1 error occurred:
	* transaction invocation failed when executing transaction: [Error Code: 1101] cadence runtime error: Execution failed:
  --> f9f3375ee02d21a3c3d936c613f0f885681e080f2653ffaff77f1016e813b947:28:28
   |
28 |                             self.modifierRef.markAttendance(currentNFT: self.currentNFT, attendance: "true")    
   |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: unexpectedly found nil while forcing an Optional value
   --> 1e3c78c6d580273b.LNVCT:295:24
    |
295 |             let ref2 =  currentNFT!
    |                         ^^^^^^^^^^^