Hi everyone,

I run my model and receive that message:

*** Failure calling solver: CONOPT4 (rc=1)

What does it means and how can I solve it?

Thank you.

## *** Failure calling solver: CONOPT4 (rc=1). What does it mean?

### *** Failure calling solver: CONOPT4 (rc=1). What does it mean?

Last edited by Yehuda 1 year ago, edited 1 time in total.

### Re: *** Failure calling solver: CONOPT4 (rc=1). What does it means?

Hi

Conopt4, as far as I can see in the documentation, came with GAMS version 25.1. Perhaps you have an older version of GAMS.

Just try 'option nlp=conopt;' (assuming you are trying to solve an NLP problem).

CHeers

Renger

Conopt4, as far as I can see in the documentation, came with GAMS version 25.1. Perhaps you have an older version of GAMS.

Just try 'option nlp=conopt;' (assuming you are trying to solve an NLP problem).

CHeers

Renger

____________________________________

Enjoy modeling even more: Read my blog on modeling at The lazy economist

Enjoy modeling even more: Read my blog on modeling at The lazy economist

### Re: *** Failure calling solver: CONOPT4 (rc=1). What does it means?

First of all, thank you for the quick answer.

Second, I do run a NLP model and my GAMS version is 24.9.2, which I bought specifically for CONOPT4 (due to previous problems).

The strange thing is that under certain conditions the model runs and reaches an optimal solution, and under other conditions, it encounters this error. Therefore, I want to know what this error means.

Thanks again,

Yehuda

Second, I do run a NLP model and my GAMS version is 24.9.2, which I bought specifically for CONOPT4 (due to previous problems).

The strange thing is that under certain conditions the model runs and reaches an optimal solution, and under other conditions, it encounters this error. Therefore, I want to know what this error means.

Thanks again,

Yehuda

### Re: *** Failure calling solver: CONOPT4 (rc=1). What does it means?

It means that Conopt4 crashed. Conopt4 was introduced with GAMS 24.8 and is still under heavy development as you can see from the release notes (https://www.gams.com/latest/docs/RN_MAIN.html). Every major release came with an update of Conopt4. So you should see if you can reproduce the failure with the latest and greatest 25.1.3 and if so you should make this model available to GAMS support (support@gams.com) so they can pass it on to the Conopt developer.

-Michael

-Michael

### Re: *** Failure calling solver: CONOPT4 (rc=1). What does it means?

Thank you Michael.

In other words, you mean that I need to purchase an updated version?

I've been working with GAMS for about two and a half years, and this is the second time I've been asking for help from you, and this is the second time the solution is to buy another version.

I was wondering if every time I have a problem that I cannot solve by myself I need to purchase an updated version?

In addition, if I purchase an updated version but the problem will not be solved, what will I do then?

Yehuda

In other words, you mean that I need to purchase an updated version?

I've been working with GAMS for about two and a half years, and this is the second time I've been asking for help from you, and this is the second time the solution is to buy another version.

I was wondering if every time I have a problem that I cannot solve by myself I need to purchase an updated version?

In addition, if I purchase an updated version but the problem will not be solved, what will I do then?

Yehuda

### Re: *** Failure calling solver: CONOPT4 (rc=1). What does it means?

Yehuda,

Precisely speaking, there is really no such thing as buying an updated version. The GAMS licensing model is based primarily on time. For example, new licenses come with 12 months of Maintenance & Support (M&S). During this 12 months (and perhaps a bit longer) you can be assured that your license will allow you to run new releases. After that time, it becomes necessary to extend the M&S to fully use the latest GAMS releases.

In your case, it's possible that the same update that enabled you to use 24.9.2 will allow you to use 25.1.3.

The details of your license can be discussed off-list with the GAMS sales team.

-Steve

Precisely speaking, there is really no such thing as buying an updated version. The GAMS licensing model is based primarily on time. For example, new licenses come with 12 months of Maintenance & Support (M&S). During this 12 months (and perhaps a bit longer) you can be assured that your license will allow you to run new releases. After that time, it becomes necessary to extend the M&S to fully use the latest GAMS releases.

In your case, it's possible that the same update that enabled you to use 24.9.2 will allow you to use 25.1.3.

The details of your license can be discussed off-list with the GAMS sales team.

-Steve

### Re: *** Failure calling solver: CONOPT4 (rc=1). What does it mean?

Hello,

some days ago, I got the latest version of GAMS (28.2.0) along with CONOPT4. And I got the same error than above.

FATAL SYSTEM ERROR Number 55668

Failure Calling Conopt4 (rc=1)

Hasn't this error been fixed yet ?

My (small) problem runs perfectly with Conopt. I took Conopt4 to be able to solve larger problems but it can't even solve this one... Is there anything new on this topic ?

Sisco

some days ago, I got the latest version of GAMS (28.2.0) along with CONOPT4. And I got the same error than above.

FATAL SYSTEM ERROR Number 55668

Failure Calling Conopt4 (rc=1)

Hasn't this error been fixed yet ?

My (small) problem runs perfectly with Conopt. I took Conopt4 to be able to solve larger problems but it can't even solve this one... Is there anything new on this topic ?

Sisco