Hi Carolina,

looking at your error message it seems you are missing this file:

3dfim+ Error: Unable to open data file: /home/cvalencia/Documentos/Subj002/func1/rest_res.nii.gz

For making a seed you can use the AFNI command 3dUndump, e.g.

echo -10 20 -30 | 3dUndump -prefix mySeed.nii.gz -master ${FSLDIR}/data/standard/MNI152_T1_3mm_brain.nii.gz -srad 4 -orient LPI -xyz -

This will create a seed in 3mm space, with a radius of 4 at the coordinates -10, 20, -30.

Cheers,
Maarten