Encountered error ' Unsuccessful in deleting the Org-chart record. The record may be in use' when user tried to delete the Organisation Chart Record. Although, they have cleared the Organization Chart at Employee Hierarchy and deleted all the modules attached to the Organization Chart at Setup > Company > Org Chart
Suggested workaround / solution(s):
Click 'Upload/Download Hierarchy Record' button to download all the reporting hierarchy items. Once downloaded, clear out all the existing employee in the Excel and re-upload the empty Hierarchy Record into the system.