Issue with calling Knitro

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John zhang

Jun 8, 2024, 10:06:51 AMJun 8
to Artelys Knitro forum
Dear expert,

I use pyomo to formulate my problem and then use ampl to call knitro to solve my problem, as show in code below.
self.solver_pyo = pyo.SolverFactory(modules.find(“Knitro”), solve_io = “nl”)

And my program contains 3 processes to solve three different problem simultaneously, with two successfully returns local optimal solution, the third one reports error with message below:
ERROR: Solver (asl) returned non-zero return code (-11)
ERROR: See the solver log above for diagnostic information.


I have checked the document of Knitro, it didn’t explain return code (-11).


So I wonder if anyone could explain it why it didn’t work ?

Appreciate your answer !

Richard Waltz

Jun 10, 2024, 12:16:42 AMJun 10

I am not familiar with these error messages.  The error messages you report do not come from Knitro itself.  Rather they likely come from the Ampl Solver Library (asl) or from Pyomo.  I would suggest contacting the AMPL or Pyomo teams to see if they have some information here.  Note that the Pyomo interface is not maintained by Artelys.


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