S Function code generation issue

I have a sfunction in the model which is referenced in a parent model.When I am trying to build the code(Ctrl+B), I am getting an error : "This is not allowed in a model configured to be referenced multiple times.To enable code reuse, the block must have a TLC implementation and the S-function's mdlInitializeSizes function must set the option 'SS_OPTION_WORKS_WITH_CODE_REUSE'. To configure the model to be referenced only once, change the configuration parameter 'Total number of instances allowed per top model' to 'One'." I changed the setting to One instead of Multiple in model referencing tab of Configuration part still the problem persists.