[Cbc] Strange behaviour of cbc

[DERHY NICOLAS]

Hi,

I am using latest version of cbc (Cbc-2.10.3-win32-msvc15).
I sometimes meet a very strange behavior when using it.

For example, with the data attached and the following command line :
cbc.exe "Model.mps" -preprocess off -ratio 1E-05 -seconds 30 -minimize -solve -printingOptions all -solution "solution.txt"
It stops after 30 seconds telling either the problem is infeasible (Result - Problem proven infeasible), either it reaches the time limit (Result - Stopped on time limit).
In both cases, the objective value seems very strange and the solution is not valid (some binary variables are not 0 or 1).
But when I read the log, it seems that some integer solutions have been found so I do not understand the final result.

When I increase the max time to 60 seconds, problem is solved : Result - Optimal solution found.
I attached the different log files.

In the past, I had similar issues with previous versions like 2.9.8. I had to downgrade to 2.8.13 to avoid them.

I know that setting "on" the preprocess allow to avoid this in that case but I do not want to do it for some other reasons.

If someone know how to avoid this, it would be great !

Nicolas




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