[Cbc] Crash when disabling preprocess

[nicolas.derhy at engie.com]

Hi everyone,

I want to report problems with CBC when I disable preprocessing.
The version I use is CBC 2.9.8 (x86) on Win7.
In the command line, I add "-ratio 0.05 -seconds 30" (for example : cbc "Crash.lp" -ratio 0.05 -preprocess off -seconds 30 -solve -printingOptions all -solution "solution_crash.txt")

I have attached two files :

-        Crash.lp : CBC stops suddenly

-        Error.lp : first, it seems optimization was completed successfully. But the objective function is clearly wrong and when I export solution, optimal value of some binary variables are non integer (vDebitNul(Interco_0,Noeud_9,Noeud_2) = 0.168948)

I tried to modify some parameters (preprocess, presolve) but nothing works.
If I activate preprocessing, everything works.

I disabled preprocessing previously because I obtained weird results and could not use optimal solution provided by CBC  in some cases. I noticed CBC generated the following message :
"Cgl0013I Postprocessed model is infeasible - possible tolerance issue - try without preprocessing"
So, it was the reason for disabling preprocessing. After that (and until these new problems), everything worked better.

If anyone has an idea to improve stability of CBC when preprocess is off, it would be great.

Best regards,

Nicolas
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