Hi, It doesn't come from the 2nd image, because I can process it alone like the first one. I got exactly the same warnings than for the first one. To be sure of my version, I download spm8b again so I should have the same line number than you now. Here are the errors obtained : Warning: Matrix is singular, close to singular or badly scaled. Results may be inaccurate. RCOND = NaN. In spm_uw_estimate>make_q at 477 In spm_uw_estimate>make_ref at 759 In spm_uw_estimate at 363 In spm_run_realignunwarp at 89 In matlabbatch/private/cfg_run_cm at 29 In cfg_util>local_runcj at 1345 In cfg_util at 686 In cfg_ui>MenuFileRun_Callback at 1129 In gui_mainfcn at 96 In cfg_ui at 53 procedure terminated abnormally: Error using ==> schur Input to SCHUR must not contain NaN or Inf.Failed 'Realign & Unwarp' Reference to non-existent field 'beta'. In file "/usr/local/etc/Matlab/toolbox/spm8b/spm_uw_apply.m" (v1358), function "spm_uw_apply" at line 226. In file "/usr/local/etc/Matlab/toolbox/spm8b/config/spm_run_realignunwarp.m" (v2337), function "spm_run_realignunwarp" at line 106. The following modules did not run: Failed: Realign & Unwarp Cheers, Cécile