Overview
...
A DUPLICATE_SCONST_FOUND error occurs when there is a Pay Component Sub Type with a Script Constant that is identical to another. This can cause reporting issues, among other problems.
...
Fortunately, this issue is simple to resolve:
How to clear a duplicate
Navigate to your Pay component subtype list: Payroll - > Payroll Setup - > Pay Component Subtype.
Change the View to PR-Script Constant to make finding the duplicate easier.
Turn on inline edit, filter by Script Constant to put them in alphabetical order, and then find the duplicates.
Find the record with the higher Internal ID - this indicates it was created later, and is likely the duplicate.
Clear the script constant field from the duplicate and turn off inline edit.