I am trying o save my data as a text or cvs file. however i keeping getting an error this values must be real

I am trying o save my data as a text or cvs file. However, I keeping getting an error "this values must be real." I know al te values are real. They have been plotted. The program is pretty simple. There is a range of variables that are used for several functions then the final output would b the Ne1(range) function. I have attached a copy of the program. Hopefully, someone has an idea on what I need to do to save this data.