Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 8fddc7b5935e1f3ab6426ed7c4aeebb6d58b2a0b9594836e718bf2811f8c5b5c:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^