Empty PayPal gateway error

Store URL: http://www.letsgrow.dk
WordPress version: 3.5.1
WP e-Commerce version: 3.8.9.5
Gold Cart version: 2.9.7
Theme:

I did this:

When ever you try to buy items using paypal as payment (Has been working for a year, and started to fail last week. I Haven’t changed the settings to Paypal API or anything else but did update shipping settings!)

I expected WP e-Commerce to do this:

Go to paypal express

Instead it did this:

SetExpressCheckout API call failed.
Detailed Error Message:
Short Error Message:
Error Code:
Error Severity Code:

Returns an empty error – I’ve googled and the verdict is that its an e-commerce error since the error is empty (not even getting to the getway) – the only solution I’ve found is a re-install of e-commerce. this is i not acceptable so I hope you can help with a better solution. At the moment the site is set to “manuel payment” wich gives me alot of extra work and alot of customers who will not accept that ..

http://ww.wp.xz.cn/extend/plugins/wp-e-commerce/