Hi list, 
I am performing a longitudinal study on surface. It is not the first time that I do it, and I have followed the guidelines at https://www.youtube.com/watch?v=M8njs_Nw...
Anyway the error listed below occurs:
Error preparing files for coregistration. Mean functional file not found (associated with functional data Desktop/Study/CONN/Arithmetic/Arithmetic_RestingState/au091223sbj01m_tp2.nii ; run either realignment or ART first, or select the option "first functional volume as reference" -#coregtomean field- if you prefer to use the first functional volume instead of the mean functional volume as reference)
Waiting for your suggestion.
Thanks
Stefano