The following extensions may cause issues with Klarna:
- non-standard checkouts (e.g. one page checkouts) may not be compatible. While the extension code is built for compatibility whenever possible, it is only guaranteed and supported for compatibility with standard Adobe Commerce checkout.
- Amasty offers many extensions for Adobe Commerce, but some of them have incompatibilities. For example, in Amasty’s Store Pickup with Locator extension, where shipping fees are altered by Amasty code after the Klarna order is created rather than after the order has been invoiced, resulting in a Klarna capture that may not match the created Klarna order. To get help with this issue, contact Amasty support.
- Innoship may block payment methods. If Klarna isn't displaying in checkout, try deactivating Innoship to confirm if it's the root cause.
While uncommon, some shops using Klarna Payments encounter a looping problem (when quote.trigger_recollect=1) with Klarna Checkout (module-kco) code that is included in the m2-klarna bundled extension. The module-kco code cannot currently be fully disabled in the bundled extension when Klarna Payments is active, but to resolve the 502 errors for an individual shop, the extension code can be updated to comment out the module-kco & module-kss code, e.g. by modifying the Model/Checkout/Kco/Session.php code. [PPP-1406]