Cause

You have inserted a device with distributed functions into the schematic. None of the functions is identified as a main function.

Solution

Turn one of the placed device functions into a main function.

1. To do this, double-click the appropriate component and switch to the Symbol / function data tab in the Properties <...> dialog.
2. In the Function data (logic) group box, select the Main function check box.
3. Click [OK].
4. If required, start a new check run.