Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> c6fe15d0f9d91734e7fb7a22c99e3f41bd4dcab0fd13cec743dc0252f12215a5:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^