Error Code10800: System error on purchasing using PayPal

I was trying to purchase something online using PayPal. My login and other information is correct (I have been trying it all over again for so many times now, so I’m really sure its correct).
But upon clicking the login button, this message shows up. I was thinking that it might just be a server downtime, but I have tried so many times and I still get the same result.
My Paypal funds are sufficient. So I can’t think of any other way that could possibly cause this problem. I have tried to purchase from other stores, but again the same problem.
It would be great if someone could tell me how to fix it and what is causing this problem.
Thanks.

System error. Please try again later.
(Error Id: 10800)
OK
