Dear John, Thank you very much for this hint. Unfortunately, I cannot find a more current update than I have installed. I downloaded the SPM toolbox last week and today I checked for a more current update with the "spm_update.m" script. It said my version is up to date. Is there another way to get the 64 bit Linux version? Thanks, Alexander -----Ursprüngliche Nachricht----- Von: John Ashburner [mailto:[log in to unmask]] Gesendet: Mittwoch, 18. April 2012 07:18 An: Alexander Hunold Cc: [log in to unmask] Betreff: Re: [SPM] Error using optimNn This message indicates that the optimNn function in your version of SPM8 has not been compiled for 64 bit Linux computers. If you download the latest updates for SPM8, you should find a compiled version of this function. Best regards, -John On 17 April 2012 23:21, Alexander Hunold <[log in to unmask]> wrote: > Dear SPM experts, > > For a MEEG source localization, I would like to segment the cortical surfaces (white and gray matter). Unfortunately during the segmentation process of an individual structural MRI, I constantly receive the following error: > > Error using optimNn (line 68) > Not compiled for GLNX64 in MATLAB 7.13.0.564 (R2011b) > > I would appreciate any help in this regard. > Thank you very much in advance. > > Best, > Alexander