Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 1ce0f4b2b17ba7344bbacc2af1f921cb4b8c009142b9b665eb17a5ad03ea7eea:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^