Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> fb4a1ca4d20d2d5b24fb16b9e5bf532f3d9c07c14bceeeeb6ce37f84378e6cc7:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^