You may receive this error when uploading grades to the grade book via the Strath CVS Grade import tool.
This shows that there was more than one Myplace profile with the same registration.
You will need to contact Myplace Support with the information listed to fix the duplicate registration numbers.
If you remove the relevant registration number - grade combination from the CSV file you will be able to continue, however you will need to manually set the grade for the affected students in the Gradebook.