Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 1efbf0cb9d7283192f04edd1ef29bc0c33d61f00b4cb641650fb43ecbe6e83fb:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^