Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 73edd6b2d52e537fa69c3fb2a30b4a2849544c5e1db5eb83bc3e4217d45ca00f:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^