Hi all, I have a binary mask that I'd like to register to an MNI-normalized anatomical ("wbrain.nii"). I'm trying to use the output file from the SPM MNI normalization of the anatomical ("y_brain.nii") as the deformation field to register a binary mask which is in native space to the MNI-normalized brain. This has worked for me on two different registrations of a native-space mask to the "wbrain.nii" file, but is currently producing the error: > In spm_maff8>loadbuf (line 78) In spm_maff8 (line 25) In spm_preproc_run>run_job (line 105) In spm_preproc_run (line 41) In spm_run_norm>normalise (line 72) In spm_run_norm (line 23) In cfg_run_cm (line 29) In cfg_util>local_runcj (line 1673) In cfg_util (line 953) In spm_jobman>fill_run_job (line 456) In spm_jobman (line 231) Warning: Matrix is singular to working precision. Has this happened to anyone else, and is there a way to fix it? Any help is much appreciated! Best, Anna