I’m seeing a similar issue on UE 5.3.1.
Does In-App purchases work for anyone on UE5.3 on iOS? I haven’t been able to get it working due to this error:
UInAppPurchaseCallbackProxy::Trigger - Invalid player UniqueNetId
This is happening because in the InAppPurchaseCheckoutCallbackProxy::TriggerCheckout() function, this line is failing on IsValid() check:
if( FUniqueNetIdRepl PurchasingPlayer = PlayerController->GetLocalPlayer()->GetUniqueNetIdFromCachedControllerId(); PurchasingPlayer.IsValid())
I have confirmed that my Paid App Agreement is valid and active, that doesn’t seem to be the issue.
Not using Game Center and that option is disabled in the certificate.
Everything works fine in a UE 4.27 build so I know the purchases are setup correctly.