Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 7fb79f63ac83ed1cadc29402b9bbbd87a7d0e8f0de01ba35cb2006eaad3045fa:15:8
   |
15 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^