This error message suggests that either your compiler is not configured correctly or that there is something wrong with your simulation.
If you are seeing this error, you should first check if you can compile the included example files in MapleSim by running one of the sample tests to make sure that your compiler is functioning properly.
If your compiler is configured properly, please check your External C-code component in your model. Be sure to check whether the external function name of the component matches the .c file name.
If the function name and the file name match, please email email@example.com and attach your .msim model and .c file.