Forking on unfeasible constraint set

[zijin8631]

after I run the manticore command, I encounter a qustions:
2023-04-22 10:04:22,187: [13718] m.main:INFO: Registered plugins: IntrospectionAPIPlugin, <class 'manticore.ethereum.plugins.SkipRevertBasicBlocks'>, <class 'manticore.ethereum.plugins.FilterFunctions'>
2023-04-22 10:04:22,187: [13718] m.main:INFO: Beginning analysis
2023-04-22 10:04:22,188: [13718] m.e.manticore:INFO: Starting symbolic create contract
2023-04-22 10:04:24,290: [13718] m.e.manticore:INFO: Starting symbolic transaction: 0
2023-04-22 10:05:30,137: [13718] m.e.manticore:INFO: 8 alive states, 1 terminated states
2023-04-22 10:05:31,490: [13718] m.e.manticore:INFO: Starting symbolic transaction: 1
2023-04-22 10:17:07,324: [13718] m.c.worker:ERROR: Exception in state 2: ManticoreError('Forking on unfeasible constraint set')
Traceback (most recent call last):
File "/home/zfc123/manticore/manticore/core/worker.py", line 137, in run
current_state.execute()
File "/home/zfc123/manticore/manticore/ethereum/state.py", line 8, in execute
return self._platform.execute()
File "/home/zfc123/manticore/manticore/platforms/evm.py", line 3106, in execute
self.current_vm.execute()
File "/home/zfc123/manticore/manticore/platforms/evm.py", line 1322, in execute
raise Concretize("Symbolic PC", expression=expression, setstate=setstate, policy="ALL")
manticore.core.state.Concretize

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/home/zfc123/manticore/manticore/core/worker.py", line 158, in run
m._fork(current_state, exc.expression, exc.policy, exc.setstate, exc.values)
File "/home/zfc123/manticore/manticore/core/manticore.py", line 518, in _fork
raise ManticoreError("Forking on unfeasible constraint set")
manticore.exceptions.ManticoreError: Forking on unfeasible constraint set

2023-04-22 10:17:41,982: [13718] m.e.manticore:INFO: 61 alive states, 5 terminated states
2023-04-22 10:17:43,290: [13718] m.e.manticore:INFO: Starting symbolic transaction: 2