Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 0d179c2b304b0b71943239a819c0ceb8d0a04d03d337ac6b55d625c3a6d2c9eb:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^