Sandbox is redirecting to /error?flowlogging_id=f699185f64292&code=BUSINESS_NAME_NOT_FOUND

[average_joe]

Hello!

Merchant ID: 78B4JNJA46HUN

For a couple of days now the sandbox at "https://www.sandbox.paypal.com/cgi-bin/webscr" is redirecting to "https://www.sandbox.paypal.com/webapps/shoppingcart/error?flowlogging_id=f699185f64292&code=BUSINESS... after each attempt to checkout and finalize a test payment. It was working fine a few weeks before that. I've verified the merchant's email address which should be the business name and it appears to be correct.

I've checked the sandbox and the developer accounts for any error logs that could give me some clue but there are none. So I'm out of options and any help would be appreciated!