Hello,

I have problems with applying the default setting P.contrast={'Omnibus F-test for PPI analyses'}.

I want to analyze a simple emotional face matching paradigm with three task regressors (Instruction, Forms, Faces) and the classical six realignment parameters (which I want to control for). 

Analysis with P.contrast=0 runs flawlessly. Turning to the default setting, the following error message appears, no matter whether I create the effect of interest myself, or let gPPI build the contrast automatically:

Not enough input arguments.

Error in beta (line 19)
y = exp(betaln(z,w));
Error in timeseries_extract (line 370)
y=y-spm_FcUtil('Y0',SPM.xCon(xY.Ic),SPM.xX.xKXs,beta);
Error in PPPI (line 461)

Following the instructions from the manual, I do not see which input I miss to define.

Thanks in advance for your help,

Marcel