Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> ff03906fdd72e14cfdf1ccab689bc5c1b4e2d6c7305e299b0306d9a83f8fb23a:15:8
   |
15 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^