Wanted to say thank you for that hint! Icould not get the toolbox run (I tried SPM8 and SPM12; Matlab2019 and Matlab2018).

This was the error:

Operands to the || and && operators must be convertible to logical scalar values.
Error in dlmwrite (line 133)
useVectorized = realdata && precnIsNumeric && ~contains('%\',dlm) ...
Error in PPPI (line 861)
dlmwrite([P.subject '_' region1 '_session' num2str(z) '_' P.method '_PPI_regressors.txt'],[OUT.PPI.C OUT.P.C
OUT.Y.C OUT.C.C],' ');
Error in runOnSampleData (line 48)
PPPI(P, [workdir filesep 'sampleData' filesep 'stats' filesep 'gPPI_sampleDataTest.mat']);
Operands to the || and && operators must be convertible to logical scalar values.
Error in rmiml.visibleInToolstrip
Operands to the || and && operators must be convertible to logical scalar values.
Error in rmiml.visibleInToolstrip

And changing the function to contains2 helped! Thanks!