Appendix A: Troubleshooting

In this section we provide examples of common error messages encountered while running Marxan, and the sort of mistakes that can cause these messages to be generated.

A-1. Marxan halts because a required input file or parameter has not been found


Marxan will halt with this message (above) if it is unable to locate the Input Parameter File (input.dat).

What to do.

1. Check that the Input Parameter File and the Marxan executable (Marxan.exe) are located in the same directory.
2. Check that the Input Parameter File name and extension read exactly – “input.dat”.

Marxan will halt with a similar error message (below) if it cannot find the critical parameter ‘RUNMODE’.


What to do.

1. Check that there is a value (and a valid value) for this parameter in the Input Parameter File. There is no default value for ‘RUNMODE’.
2. Check that the parameter is labeled correctly; it must be in all capitals with no spaces or extra characters. (This is done automatically if Inedit is used.)

Marxan will halt with this message (below) if it has found the Input Parameter File but has been unable to locate one of the remaining three required input files.

1. The type of input file that is missing (in this example it is the Conservation Feature File, a.k.a. the Species File).
2. The name of the directory that Marxan is looking for the input files in. This is the name specified in the Input Parameter File.
3. The name of the file Marxan is looking for. This is the name specified in the Input Parameter File.

What to do.

1. Check that the name of the directory containing the input files is the same as the name given in the Input Parameter File under the variable, Input Directory (‘INPUTDIR’).
2. Check that the directory containing the input files is either located within the same directory as the Marxan executable (Marxan.exe) or the location has been correctly specified in the Input Parameter File.
3. Check that the name of the file given in the Input Parameter File exactly matches the name in the input file directory.

A-2. Marxan halts because of an unrecognised identifier

In this example (above) the error is because of an inconsistency in the Conservation Feature (a.k.a. Species) IDs. This error could also have the term “Planning Unit” instead of “Species”.

This error will occur if there is inconsistency in either the Conservation Feature IDs or Planning Unit IDs between files. In other words the IDs listed in the Conservation Feature File or Planning Unit File are not the same as those in the Planning Unit versus Conservation Feature File (and vice versa).

What to do.

1. Check that conservation feature IDs listed in the Planning Unit versus Conservation Feature File exactly match the IDs in the Conservation Feature File.
2. Check that planning unit IDs listed in the Planning Unit versus Conservation Feature File exactly match the IDs in the Planning Unit File.

A-3. Marxan begins the first run but then halts because it is unable to save the required outputs

1. The message identifying that Marxan is unable to save the desired output.
2. The name of the directory Marxan is trying to save the output files in (in the example the error is because of a space between the words ‘out’ and ‘put’).
3. The name of the file Marxan is trying to solve when it encounters the error.

What to do.

1. Check that the name of the directory you have established to save the output files in is the same as the name given in the Input Parameter File under the variable, Output Directory (‘OUTPUTDIR’).
2. Check that this directory is either located within the same directory as the Marxan executable (Marxan.exe) or the location has been correctly specified in the Input Parameter File (This is easily done using Inedit).
3. Check that the name of the file given in the Input Parameter File exactly matches the name in the input file directory.

A-4. Marxan runs but warns you it is unable to find a particular variable

Marxan will report this warning when it is unable to read the value for some parameter in the Input Parameter File. This may either be because a value was not specified, or there was a formatting error. Marxan will still run normally but will use the default value for that parameter.

What to do.

1. If you intentionally did not state a value and are happy for the default value to be used, do nothing. Marxan will run as normal.
2. If you do not wish to use the default value, check the following:
   • That the Input Parameter File (input.dat) contains a value for the missing parameter.
   • That the parameter is correctly identified in the Input Parameter File. Its name must be in all capitals with no spaces or additional characters.
   • Check that there is a hard return at the end of the Input Parameter File.

Note: Do NOT worry about the line that reads “WARNING unable to find HIGHDATA”, this refers to a now defunct parameter in Marxan. Marxan will run correctly and as intended even when this warning is displayed. This error message will not show up in future versions of Marxan.

A-5. No outputs are being saved in the output directory
What to do.

1. Check that an output directory has actually been specified in the Input Parameter File. If no directory is specified then Marxan will not save any outputs.
2. Check that you have selected the outputs that should be saved. This can be done by looking directly at the Input Parameter File; all output to be saved should have the value ‘1’ next to them. Outputs you don’t want saved should have the value ‘0’ next to them.

A-6. Marxan crashes as soon as it is executed and the Marxan screen closes
This may happen for a variety of reasons but most typically if there is a value missing from the input data files. If you are running Marxan on a Windows machine this may also be accompanied by the following error message:

If this message appears, please feel free to let Microsoft know. We very much doubt, however, that they will do anything about it. Marxan is not a big money earner for them.

What to do.

1. Check that there are values for all variables in each of the input data files. This includes the three required files (Conservation Feature File, Planning Unit File and the Conservation Feature versus Planning Unit File), and the two optional files (the Boundary Length File and the Block Definition File). For each of these files there must be a complete set of values for all required variables and any of the non-required variables that are being used.
2. Check that there is not more than a single hard return (blank lines) at the end of each of your input file.

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