This is happening to me too. I think it's a PayPal setting on Deeper Network's Paypal account:
PayPal Error: Things don't appear to be working at the moment.
Customers are receiving error: Things don't appear to be working at the moment. Please try again later.
This error typically occurs for a couple reasons:
Incorrect PayPal Settings
It's possible you have entered your PayPal email address or PayPal Identity Token incorrectly. Please confirm your PayPal email address and PayPal Identity Token are entered correctly within Downloads →Settings → Payments → PayPal Standard
Encrypted Website Payments
Your customers may also see this if Encrypted Website Payments set to ON. Setting it to OFF will resolve the issue. This setting can be adjusted from within your PayPal account by following these steps:
(1) From your PayPal account, hover over the cog in the upper right corner of the screen and click Account Settings
(2) On the next screen, click Website Payments on the lower left
(3) On the right side of the screen, click Update next to "Website preferences"
(4) Make sure the option under "Encrypted website payments" is set to OFF