Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> bccd44a2fc845b5c7dafb615e24f78d09a0e55fd00c1ad52bc25e6aa6b6b9bec:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^