aCompcor returns confound timeseries filled with zeros


I ran sMRIPrep to generate anatomical derivates. Then I used the WM, GM, CSF probability segmentation masks as input in aCompcor masks of fMRIPrep to generate CSF, WM and CSF+WM and fed the newly generated maps(I checked these maps in fsleyes and they are fine) into aCompcor standalone module hence in the outputs it generates empty files without any errors or warnings. May I please any guidance on this? I have been stuck on this for awhile to run aCompcor as a standalone module Thanks.