Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 3da04d8ac249c3b3cb4400ef7a36962218f9aa230327ed8f5cdcd36910b1a5e2:15:8
   |
15 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^