Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> b81bb40d9cb40bfeba8bd4cfd94431dab948182f64e2fdd92667fa6fb01b0d3d:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^