This error indicates that there is a training history record linked to the course that is failing to delete.
To find who has the linked record, you will need to follow these steps.
In the Admin Tool, click Import/Export Data.
Click Create an export definition.
Click Select the data to export.
Change the database to SelectHR.
Log in.
Copy the below SQL:
Select Course.Events.[Course Start Date], Course.Events.[Course End Date], Course.Events.[Course Title], Course.Events.[Course Number], Course.Events.[Event Number], Training.History.*, Person.Snapshot.[First Name], Person.Snapshot.Surname From Course.Events Inner Join Training.History On Course.Events.[Event Number] = Training.History.[Event Number] Inner Join Person.Snapshot On Training.History.[Person Number] = Person.Snapshot.[Person Number] Where Course.Events.[Course Title] = 'ENTER COURSE NAME'
Once you have identified the person with the training record, go to their training history to delete the record.
If you require further assistance, please raise a new case online and reference the title of this article confirming the following details: Course Name and the date of the course.