Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 75ee6ec1f080a83ee6cf53aaf78152f4c3f220e82cf36d26bf8b59c1e417ef5d:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^