Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> e51aaf57a68ebcaf4bc987b38fdfc04a4b3ef077304f0cf3744dea7cac4ece01:15:8
   |
15 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^