I am running 1.39D and getting the same error. PayPal Direct payment error 10413 and PayPal express checkout error
10413 Transaction refused because of an invalid argument. See additional error messages for details. - The totals of the cart item amounts do not match order amounts
It does not happen all the time many payments go through fine but almost daily we will have one or more failures with that error code.
I asked a customer who had the problem to let me know what he was trying to buy. I tried to buy that item paying by card wnd could not but. I looked at the prices both net and gross were to 4 decimal places rather than the one originally entered (prior to upgrading from 1.37) being to 2 decimal places and the other that was auto calculated would be to two. Changed that I could buy. Tried others that were likewise priced both to 4 dec places without success. Then tried to buy one item but changed the prices.
If gross price is 17.95 and net works out as 15.2766 I cannot buy and get the totals do not match error. Change price to 17.17 with net at 14.6128 I can buy no problem no errors.
I cant go through all items on the site to fiddle with prices so they are all in the sweet spot. If I did I might then find that there are sweet combinations of prices for sales of multiple different items.
I cannot fathom it. Any ideas please?