Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 67e9a1bbca31b3f07d887d3bfd2a0314e18d3a3e5eaa33d8bb39ebdfda34a19c:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^