Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 74ae4bb7ee0b20cc3767955a2ee0b19f1703ed8e161abb04ddd753d9a6565b7d:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^