Has anybody came across, after update to Magento 2.3 a "Unique constraint violation found" error when generating a shipment? I could only find answers with same error regarding categories or products.

There was bunch of errors in Klarna checkout module 7.1.0, and I updated it to 7.3.0 - now the payments are getting through.

For the "Unique constraint violation found" error, Magento doesn't add anything to logs. So it's kinda hard to check where it comes from.

It looks like a database issue, but even if I use backup sales tables from before the update to 2.3, the error still persists.

Can the error be generetad from Klarnas side and just displayed on Magentos backend?

How can I find what's causing the error in the first place?

Thanks for u all!

1 Answer 1


Duplicate ID issue in the Sales Order or Order Payment tables. Please check new order ID or duplicate ID in the tables.

  • Thanks Ashvini, but can't find dublicates. Also in sales_order_payment table the paren_id:s are paired correctly and in klarna_core_order table the order_id. New orders reveive new id:s. Any other ideas?
    – MaxPower
    Aug 19, 2019 at 14:46
  • @MaxPower did you found the solution?
    – huykon225
    Mar 24, 2021 at 2:38

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