Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> eff3664f88fd6dc0fad28a5c9a1bf7fb7a9be1c4ef0cdc64b68f0300a8ec4d23:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^