Hello,
This is a common error message, this occurs when a business transaction tries to update a duplicate record.
The solution is to Not input a duplicate value.
Advise the user (whoever is impacted by this) to check the data that is being entered, if the user cannot understand which data is duplicate, you would need a technical consultant to run a debug on the business transaction that is causing this error to trace which value is duplicate.
Regards,
Siddhesh