User Tools

Site Tools


This is an old revision of the document!

Check List before contacting the GAMS support

Here are several reasons why you may want some help:

  • You think GAMS does not do what it should do
  • The solver has problems in solving your model
  • GAMS has problems with your hardware or operating system
  • You are stuck with a modeling or formulation problem

Of course we cannot do all the modeling work for you (unless you hire us as a consultant) but we have lots of experience in using GAMS in both small and large, complex modeling situations in all kind of different application areas, ranging from economics to chemical engineering. Just talking to us for a few minutes may put you on the right track again.

In case you think GAMS or the solver fails, please provide us with as much relevant information as possible, such as:

  • Your operating system
  • GAMS version and solver used
  • Size and structure (linear, nonlinear etc.) of the model

Most of these information are included in the log file:

  • If you are using the GAMSIDE, there will be a file called model_name.log in your GAMS project directory. Alternatively you may just copy and paste the content of the process window into an e-mail.
  • If you are working from the command line, please use the additional command line option lo=2 (e.g. gams trnsport.gms o=2) to redirect the screen output into a log-file.

Find below an example of a log file (trnsport.log):

--- Job trnsport.gms Start 05/16/08 14:58:33
GAMS Rev 227  Copyright (C) 1987-2008 GAMS Development. All rights reserved
Licensee: Franz Nelissen                                 S080428/0001CN-WIN
          GAMS Software GmbH                                         DC3459
--- Starting compilation
--- trnsport.gms(69) 3 Mb
--- Starting execution: elapsed 0:00:00.004
--- trnsport.gms(45) 4 Mb
--- Generating LP model transport
--- trnsport.gms(66) 4 Mb
---   6 rows  7 columns  19 non-zeroes
--- Executing CPLEX: elapsed 0:00:00.009

ILOG CPLEX       May  1, 2008 22.7.2 WIN 4792.4799 VIS x86/MS Windows
Cplex 11.0.1, GAMS Link 34 

Reading data...

Please send us that file.

If possible also attach a (zipped) copy of your model and all necessary data files, which will allow us to reproduce the problem. If there are include files or other data sources, please use the dumpopt parameter to produce a single source file. In case there are confidential issues, you may send us a scalar version of your model, see: for instructions abut that and the usage of the dumpopt option.

Our e-mail system can handle attachments up to 15MB, if you have to send us larger file we recommend to use a free exchange file provider. We have made good experience with

As a security measure to prevent potential viruses, our mail system does not allow users to receive executable files (such as files ending in .exe, bat, or cmd), even if they are sent in a zipped (.zip, .tar, .tgz, .taz, .z, .gz) format. Any message of this type sent to us will be bounced back you. Adding an underscore to the file attachment (e.g. file.zip_) may help.

IMPRESSUM / LEGAL NOTICEPRIVACY POLICY check_list.1210942750.txt.gz · Last modified: 2008/05/16 14:59 by support