Two months ago, I used the Paypal sandbox site without problem. But recently it took me all day, I don't know what happed with their site.
Yesterday, I tried many times to create new sandbox account after I logged in registerd Business account. Almost times Paypal sandbox site raised some kind undefined errors from sky which I never met. Even I succeeded to create Business sandbox account, that account did not contain any information of API (as I said, it have worked before).
Today, I tried to create other account again, luckily, the API was generated. But in the morning when I logged in sandbox.paypal.com, the site is always broken (layout and CSS were gone and I viewed it on many types of browser)
I was lucky again, until the afternoon, I can access to the sandbox busnisess account after I logged the main Paypal Business account. But I still met other problem: I could not access to the History tab, it always redirect me to History tab OF MAIN PAYPAL ACCOUNT, NOT SANDBOX ACCOUNT. I did research and put the following URL
https://www.sandbox.paypal.com/us/cgi-bin/webscr?cmd=_history&nav=0%2e3
but they keep throwing the error: "We'are sorry, the process ...." Any one experienced it?
Today it is working again. Maybe Paypal sandbox site has bug and they have fixed it.