Hi,
I understand that you are encountering an error message “Error loading external input data.” while running the Simulink model.
I see in the model the system is the top-level system and is not part of any subsystem. But you have given input to the system with the help of “inport” block.
The “inport” block links a signal from the outside/external system into current system. Since in the model there is no external system, you are encountering this error.
To resolve this problem, you can create an external system and then link that signal to your system, or you can try to give input directly from workspace or with the use of other blocks.
To know more about the “inport” blocks refer the documentation attached below.