Open your model.

If your model contains errors related to callback functions, the Diagnostic Viewer opens and displays the following errors in Model Load stage.

In the Simulink Editor, in the Modeling tab, select Model Settings > Model Properties, and examine the callback error.

After fixing any callback errors, simulate the model to diagnose simulation errors and warnings.

Diagnostic Viewer lists errors and warnings in stages. Each stage in Diagnostic Viewer represents a single event such as model load, update diagram, simulation, or build.

To address errors first, click and to filter out warning and information messages.

To locate the source of the error, click the hyperlink in the message. The model in the source is highlighted. If a block has multiple ports, you can hover over each port to see the port number.

After fixing all errors, simulate your model again and view the Diagnostic Viewer to identify remaining problems.

If an object in your model generates a warning that you do not want to be notified of, sometimes, you can suppress the warning from the specified source using the Suppress button. You can restore the warning from that source using the Restore button. For example, if a Counter Free-Running block generates an overflow warning that is intentional in your design, you can suppress only overflow warnings from this particular block, without sacrificing notification of other overflows in your model.

To generate code for your model, in the C Code tab, click Build.