In the end the way I found to resolve this (and apologies if this had been previously mentioned in the forums but I couldn't find it by searching) was to declare `global defaults` on the command line, and then add mat.format field by hand.  

I also renamed the `contains.m` file in the toolbox to `old_contains.m`.  

This is still not working, in that I get the following output, but I'll try to contemplate this for a while before posting a new question.

runOnSampleData

spmpath =
'/Users/katie/neuroimaging/spm12'
P =
struct with fields:
subject: 'sampleData_Study'
directory: '/Users/katie/neuroimaging/NITRC-multi-file-downloads/running_gPPI_generic/sampleData/stats'
VOI: '/Users/katie/neuroimaging/NITRC-multi-file-downloads/running_gPPI_generic/rmedPrecCing.nii'
Region: 'rmedPrec'
analysis: 'psy'
method: 'cond'
Estimate: 1
contrast: 0
extract: 'eig'
Tasks: {1×13 cell}
Weights: []
equalroi: 1
FLmask: 0
CompContrasts: 1
Contrasts: [1×2 struct]
Log File: sampleData_Study_PPPI_8_4_2022_4.log
PPPI Version: 13.1.4-17-2014
Parameters used:
Processing subject: sampleData_Study
VOI file : /Users/katie/neuroimaging/NITRC-multi-file-downloads/running_gPPI_generic/rmedPrecCing.nii
Output file will be: sampleData_Study_rmedPrec_session#_cond_PPI_regressors.txt
Contrast : No adjustment
Analysis : Psychophysiological Interactions
Extraction : eigenvariate
Tasks : _0_etoh_on_onsets_run1_etoh_off_onsets_run1_etoh_urge_onsets_run1_attn_on_onsets_run1_attn_off_onsets_run1_attn_urge_onsets_run1_etoh_on_onsets_run2_etoh_off_onsets_run2_etoh_urge_onsets_run2_attn_on_onsets_run2_attn_off_onsets_run2_attn_urge_onsets_run2
Method : Condition Specific
VOI has 549 voxels in 3x3x3 space
VOI has 549 voxels in 3x3x3 space. This is in the the same space as the input data and functional mask.
VOI has 549 voxels in 3x3x3 space
VOI has 549 voxels in 3x3x3 space. This is in the the same space as the input data and functional mask.
Estimation Failed
Warning: Missing conditions!!! Invalid Contrast
Invalid Contrast
Warning: Missing conditions!!! Invalid Contrast
Invalid Contrast
PPI Contrasts were not estimated for some reason.