Comentário oficial
Please make sure that your formatting is EXACTLY as it is in the sample. Open your GCP file in a plain text editor like Notepad or TextEdit to look for weird new lines or empty data.
If the table at the bottom if filling in properly it might be an issue of you transposing the Lat and Long columns. Zoom way out on the map and see if the markers are somewhere else on the map. All the way out.