Gurobi License Expired

[Mark Underwood]

Hi all,

I have an issue with running Optano using gurobi.

Im getting the following readout from my debug window:

Set parameter WLS AccessID 

Set parameter WLS Secret 

Set parameter LicenseID to value 2439354 

Limited License is expired. Please upgrade to the latest Optano Modeling package"

Previously, this was working fine. I then took out a trial license for a size-unlimited version of gurobi, set my environment variable to point to the new license and happy days for the duration of the trial.

Upon completion of the trial i assumed i could fall back to the built in limited version that ships with optano. upon receiving the above message i made sure to remove referrecnes to the upgraded license, and referencing environment variables. still same error.

i tried setting the gurobiconfig properties to fallback behaviour on LimitedLicenseUsage to force the issue. same error.

ive tried taking out an academic license on gurobi, installing that license and explicitly setting gurobi config in my code to reference the new license. same error. important to note that it still looks at the above ID (an expired one) regardless of whether i point it explicitly to the new license. 

Ive also made sure to remove all packages and references to optano and gurobi and install the latest versions. same error.

any help, greatly appreciated

[Jannick Lange]

Hi Mark,

the size-limited license of the previous modeling version(s) has expired on Dec-31st.

I have just uploaded a package with renewed licenses to the public nuget feed:

* https://www.nuget.org/packages/OPTANO.Modeling/3.21.0.641

* https://docs.optano.com/modeling/3.21.0/changelog.html

If you update to the references version, the limited license should be working again (given that you use Gurobi 9.5 or later). Please excuse the inconvenience.

Best regards,

Jannick

(Sorry, if this will become a double-post. My last message seems to have disappeared somewhere in the nirvana...)

[Alejandro]

Hi,
What does size-limited license mean?

What limitations does Gurobi's limited license have?

I want to know if Gurobi works for my project or should I use some other free alternative
I appreciate your help.

[Jannick Lange]

Hi Alejandro,

"Size limited" means that the model is restricted to 2000 variables and 2000 constraints. (Don't pin me down on the exact numbers, but it's something in this order of magnitude).

Depending on your model, this might or might not suffice. However, once you have implemented your model, you can easily swap out the solver if you find out that the limited license will not work for you.

A free alternative would, for example, be the HiGHS Solver, which is also supported by OPTANO.Modeling:

* https://github.com/ERGO-Code/HiGHS

* https://highs.dev/

Best regards,

Jannick