Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> fdf97fb9b558fa250a2f4f9c6e21ceec2d92d1c96b7ceb67df2556157cf6f56d:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^