Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> a408cd72a5f8a1ba978fa83d9af3baeb498878e82046e4218ad9ffb6c0cbf74c:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^