Determine which initialization mode to use.
In most situations, using simplified mode offers many benefits. To determine which mode to use, see:
Set the initialization mode using the Configuration Parameters > Diagnostics > Data Validity > Underspecified initialization detection parameter. Set the parameter to either Classic (default) or Simplified.
If you use simplified mode, you might need to modify your model to change the initialization mode for an existing model that is in classic mode to use simplified mode. For details, see Convert from Classic to Simplified Initialization Mode.