I am getting an error called "Block/State '...' present in initial state is missing in the model" while running model linearizer tool.

I am working on a power converter. To tune the PIDs, I tried to use the model linearizer tool to linearize the model and then use the bode plot to tune the PID Controller. So first, I took the snapshot at steady state. I choose the fixed sample time sine stream as input perturbation with frequency ranging from 1KHz to 150KHz. But when I try to plot the Bode. It gives me an error that "Block/State 'SimulinkFileName/PWM Generator (DC-DC)/Sawtooth Generator/Model/Unit Delay ' present in the initial state is missing in the model 'SimulinkFileName'." I have not changed anything. Can anyone please help solve this?