Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 2a5f1b9eb744cc52bfc5d872e551d89e8bc1ee5a7cfbe7a09cddf0ed053f3bcc:15:8
   |
15 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^