Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> cb6a7d09ab400da5df0b3bc1c4772a0bb3edde8b7e1ca9c5dd757830ff5061c8:15:8
   |
15 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^