Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 8fa9d181bc51cc1c3bff2654f1f69698e5cf5a2c46ee8da9ff5c9df1a1d39c9d:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^