Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> b4dc51b690032d7fdb82d3c2ea2bed727b8084cf5d372427e9d7b81f0f88fb0b:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^