Dear SPMers, I have created a mask, using pickatlas 2.4, which I am trying to use as the explicit mask in the 2nd level analysis. However, I receive the following error: Running "Factorial design specification" Mapping files : ...done Design configuration : Error running job: Error using ==> spm_vol>subfunc /birc/lsmlab/8330/results_all_non/mask.img: Unknown file format.i -------------------------- Additionally, all the mask files are deleted after this error. Any ideas as to why this is happening?