Problem fitting a Gaussian

Hi all,

I have a spectrum that I need to fit a Gaussian to a peak in the energy range 339 to 351 keV. I am trying to use Roofit to do this. I cannot load the data as each time I get a segmentation violation. Can anyone advise me what I am doing wrong? This is the first time I am using Roofit.



We need a simplest an shortest example from you showing this problem