Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 7c56fd1ecc0bab3154ffc1eaac31c4e6d3f0dce7501fe9faa695ac181f1d8de3:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^