Transaction

[Error Code: 1101] cadence runtime error Execution failed:
error: underflow
  --> 3a8a15e2ac739ef843b8ce8cfcf66d8aa032e1a23121e24d8bd21084ea3b31a0:16:8
   |
16 |         let total: UFix64 = SwapConfig.ScaledUInt256ToUFix64(res) - 0.2
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^