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 used in your model. It may be possible that there is a mistake in the code (Eg. spelling, case sensitivity, undefined variables)
If the model and code appear to be correct, please email firstname.lastname@example.org and attach your .msim model and C file.