One of my simulink model works fine in R2009b. But not in R2012b. Following is the error thrown while trying in R2012b. " 'msk_out_dt' does not resolve to a valid data type for parameter 'OutDataTypeStr' ". This error is pointing to a datatype converter block. where the output data type is mentioned as "msk_out_dt" which is derieved from the top of the masked subsystem. But the masked subsystem is kept inside the Stateflow. There are somany level of subsystems. I'm unable to share the simulink model, However any clue is appreciated.