[SCIP] After stopping pricing and doing restart, model is becoming unbounded during presolve?

[Franzen, Christian]

Hi Scip Team.


Thanks to the help of Gregor, I managed to make SCIP stop pricing after some iterations and doing a restart on the reduced master without pricing. Unfortunately, I am facing some really strang behaviour. Sometime it happens, that my model (for that I already have found a feasible solution), is reported to be unbound. I wrote the corresponding LP files before and after presolving to disk and I see that some variable bounds vanished, which seems to be the reason for the unboundness. Furthermore, some of the objective coefficients changed their sign. Any ideas how or why that is happening during presolving?


Regards

Christian


P.S.: I attach the SCIP log for one of these runs.
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