Gurobi fails to generate an environment in amplpy

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1

Hello everyone,

Starting today (2024 Nov 19), I failed to run my model within the amplpy API using Gurobi (12.0.0). The following message is returned in the console:

Gurobi 12.0.0: Could not create gurobi environmentexit value 2 <BREAK>

I tried to uninstall and reinstall ampl_gurobi module for amplpy and it is updated to the latest version for Windows (20241114) but the problem still remains. I have also tried to re-update the AMPL licence (community-academic edition), without success.

If I try to solve the model by switching to a different solver like IPOPT, I do not face any problems.

Until yesterday, ampl_py solved the model with Gurobi (12.0.0) without issues.
Is there anything that I can do to solve this problem?

I really appreciate any help you can provide.
Gianmarco.

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2

Hi @Gianmarco,

Thank you for reporting this issue. Gurobi 12 has just been released with release 20241114.

Could you please try installing version 20240808, which is the last release with Gurobi 11?

3

Hi @fdabrandao,

thank you for your quick response. I confirm that downgrading to ampl_gurobi 20240808 (and hence to Gurobi 11.0.3) solves the problem.

Thank you again.
Best,
Gianmarco.

1 Like
4

Hi @Gianmarco,

We have just released Gurobi 20241119. It is Gurobi 12 with this issue fixed.

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