The following is for '''MonteData -> MSM -> Genetic Algorithm''' Figured out that the value "W" in msmf_corr_coeff.m is an empty vector. <br> When it is multiplied by mm-M0 (which always happens to be 0), it returns an empty vector <br> This is why the error suggests the fitness function must return a scalar value <br> When I assign W =6 for example, the program runs just fine. <br> I need to figure out what W does and how it is assigned in order to fix this issue. <br>