DearAll, I was just trying to run the randomize step of FSL-VBM and get the following error message: Loading Data: *************************************************************** Data loaded ERROR: Program failed An exception has been thrown Logic error:- detected by Newmat: incompatible dimensions MatrixType = Rect # Rows = 56; # Cols = 56 MatrixType = Rect # Rows = 63; # Cols = 208920 Trace: MatrixMult. Exiting Does anyone know what the cause could be. I have run the exact same command on a subgroup (and adapted design matrix file) and it appears to be doing fine. Thanks, Hannah