^^
This!
It was the only thing causing my 601 Error when I had it....damn crazyness!
I had same issue, I got error 601 then after trying a third time with a different card I got error 401.
I ended up doing the UltimatePay way and it worked...kinda dum to have to do this, but still worked out.
>Mogstation >https://secure.square-enix.com/accou...svc/mogstation
>Add Crysta under (Square Enix Settings tab)
>Click on amount of Crysta you want to add to account (I did Specify amount of 1500 for $15)
>choose UltimatePay
>PayPal
>sign into paypal
>process payment
>back to Mogstation
>proceed to payment
>add Crysta as payment to account
>next complete
Hope it helps.
Worked fine for me after allowing stuff though Not Script on Chrome. So everything is A-ok here.