here is my terminal output:

register: ### can't create file NULL/rgb/NULL

I think maybe this is a very stupid question:)

________________________________ De : Hao wen Envoyé : mardi 7 juin 2016 10:27:07 À : freesurfer@nmr.mgh.harvard.edu; Bruce Fischl Objet : Save REG in tkregister2

Hello:

I am using tkregister2 to do some manual registration, but I can not save reg with the button in the GUI