Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 8578bd573bd9ed99dc7ae6bd8081bd713e5edcb7ad89b9e1f75f03a550bee3fb:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^