Genetic algorithm error in 'fitness function evaluation'

hello,

I wrote a code about the genetic-neural network. every time I run it, face this error in the function of fitness evaluation. my cod is:

function EE=FitFcn2(particle)
global  sigma rule Train_data Target_train
M=size(rule,1);
w(:,1)=particle(1:M);
c=reshape(particle(M+1:end),size(sigma,1),size(sigma,2));
 EE=0;
  for ii=1:size(Train_data,1)
        x=Train_data(ii,:)';
       
    o=FS_type_1(x,c,sigma,w,rule);

        e=Target_train(ii)-o;
        
        EE=EE+sum(e.^2);
  end
    EE=EE/size(Train_data,1); 

the error is:

Error in main2 (line 13)
    [w,Fval,exitFlag,Output]=ga(@(w) FitFcn2(w),num_v,...

Caused by:
    Failure in initial user-supplied fitness function evaluation. GA cannot continue.

how can I solve it? what does this error exactly related to?