Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 1aded86bf2ba92e90a6009bb8e4a8e491ef789d2349bc4d2d1efdcd2e2f7b500:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^