Convolution of voxel-dependent stimulus function with HRF

Hello AFNI gurus,

I would like to do the convolution of a 3d+time dataset that contains stimulus times series for each voxel (e.g. this could be the output of a whole-brain 3dTfitter or 3dPFM analysis) and an IRF that is saved as .1D file. I tried to use 3dConvolve but without too much luck. Here is the command (although I tried several combinations of options considering that convolution is commutative, i.e. xy = yx):

3dConvolve -polort -1 -input stims+orig. -num_stimts 1 -iresp 1 HRF.1D -output stims_fitts
++ 3dConvolve: AFNI version=AFNI_17.0.09 (Feb 10 2017) [64-bit]
++ Authored by: B. Douglas Ward
++ 3dConvolve: AFNI version=AFNI_17.0.09 (Feb 10 2017) [64-bit]
3dConvolve Error: Unable to open IRF file: (null)

How could it be done?

Thanks in advance,