3dDeconvolve thinks input Nifti is 5D

From seeing "Alexios V Doukas the Bushy-eyebrowed", I think that means you are using a singularity instance built by NeuroDocker.

And actually, another thread that mentioned a similar "AFNI can't deal with 5 dimensional NIfTI" error had that kind of singularity, too:

Hmmm....

--pt