Dear SPM users, I was working on 15 subjects and the first 8 had no issues while I started running into this problem at the 9th and 10th subject. I simply realigned and then attempted to do slice timing correction but when I ran slice timing module, I got this error: Running 'Slice Timing' SPM8: spm_slice_timing (v3756) 15:34:23 - 22/04/2011 ======================================================================= Your TR is 2.2 Failed 'Slice Timing' Improper assignment with rectangular empty matrix. In file "C:\Users\shaza\Desktop\spm8\spm_slice_timing.m" (v3756), function "spm_slice_timing" at line 232. In file "C:\Users\shaza\Desktop\spm8\config\spm_run_st.m" (v2312), function "spm_run_st" at line 25. The following modules did not run: Failed: Slice Timing Any suggestions?