Check ID:
com.mathworks.HDL.ModelChecker.runInvalidDUTChecks
Check for subsystems that cannot be at the top level for HDL code generation.
This check verifies whether your Subsystem is a valid DUT for generating HDL code. For example, if you use an invalid DUT such as an Enabled Subsystem or a For Each Subsystem block, this check displays a warning and provides a link to the Subsystem.
To fix this warning, place this Subsystem inside another Subsystem, and then use that Subsystem as the DUT. You can then rerun the check.