Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> a76007fde0b0fc8e565e580a3d9ef7fc6d3d6e900980a8e615aa83fb1e4f66fc:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^