The pseudocode below is provided for Iterated Local Search solving a minimisation problem. Which line of the code is problematic, and why?

1 s*= GenerateInitialSolution()
2 Repeat
3    s' = applyLocalSearch(s*) // apply hill climbing 
4    s' = perturbSolution(s' ) // make a random move
5    accept = moveAcceptance(s*, s', memory);  // remember best solution found so far
6    if (f(s') < f(s*)) s* = s'; // else reject new solution s'
7 Until (termination conditions are satisfied) 
8 return s*