It shouldn't be saying MODULE_PAYMENT_AUTHORIZENET_AIM_CURRENCY in the logs, nor in the transmission (it should auto-translate that to the config setting you've selected). That suggests that you haven't configured the AIM module in your store. I know that sounds dumb because I'm sure you've done that. But the only way it would do that is if it's not set yet, and that requires editing the module in your store's admin payment modules screen.

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