Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> d75ec86b29f0c25de66ba6ee1e8eeb35b4cb3ae5e70ecb16f6e3eefbf0f4fa2d:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^