Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 3b9e7d0cdf5b07e03e80a0636b8432818a8d1581af74982fb6fb7cf0fbf9d3c5:15:8
   |
15 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^