Can't upgrade account

I’m trying upgrade my account to basic plan with my credit card, but I’m receiving this message all day:
“PayPal Server Error: This transaction cannot be processed at this time. Please try again later… 10764. This transaction cannot be processed at this time. Please try again later.”
Someone could tell me what’s going on? thanks =]

@Guilherme_Silva - Unfortunately, this sometimes seems to happen with recurring payments from Brazil through PayPal, our payment provider. If this keeps happening you should be able to upgrade by buying a 6-month or 12-month membership here - Login - LingQ. These are 1-time payments so they should work.