Digital Filter Design block error, filter not valid, please redesign.

I am using MATLAB R2025b and trying to design FIR filters using window function in Simulink using the Digital Filter Design Block, when I run the model it gives an error message box saying: "fliiter design is not valid. please redesign". I tried generating MATLAB code of the block and the code runs with no errors.

parameters I used:

low pass filter

rectangular window

order = 50

Fs = 48000 Hz

Fc = 10800 Hz

[Walter Roberson]

What Response Type and what Design Method did you specify ?

[Ahmed]

response type: Lowpass

design method: FIR (Window)

[Ahmed]

[Ahmed]

[Walter Roberson]

In my testing, I could not replicate the problem.

Could you perhaps attach your model for testing?

[Ahmed]

This is the model, I'm building FIR low pass filters using different window functions and all of them give the same error message.

[Walter Roberson]

Hmmm, I don't know.

I went into the block and commented out all of the filter types except for one. I then played with the filter settings. As long as the setting was Window, the details of the Scaled windowing made a difference. Most of the settings generated that error, but a couple of them did not generate any error. I added a scope block at the top level, and I observed that valid-looking signals were generated whether or not the error message was generated.

[Ahmed]

Oh, the output does look valid regardless of the message, thank you for your assistance.

[Anumeha]

Hi Ahmed,

Seeing the discussion above and getting the same error while trying with R2025a, I think the error can be ignored.

You can also report it as a bug at https://www.mathworks.com/support/bugreports/

[Ahmed]

The error stopped showing up after I set a value for the sample time for the sin wave (1/48000 (filter's sample time)) and changed the solver options to:

fixed step discrete fixed step size = 1/48000

I didn't test which solved the error