Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> cb019d69af8ee9bf3dc5e8c5b6a7c540ccefbbd83ac364c0ac1bd98d247b7b7b:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^