This error can only be resolved on Census day itself.
School lunch taken only required from pupils in reception, year 1 or year 2 or from pupils aged 4 to 6 in year 'X'
1) Go into the relevant census via School > Data > Export > Data Returns - select School Census in the slide over menu
2) Select Meals on the left-hand side menu
3) This will take you to a screen where you can add the number of meals taken on the day with school meals