Eight days ago, PayPal broke their Buy Now buttons ^[1] for customers who sell electronic goods (i.e. who don't collect shipping addresses).
The error is because they use `eval()` in their JavaScript, which browsers block. So far, they have been unable to fix the issue.
If you are a PayPal merchant using a payment button who sells digital goods, this might be why your payments stopped over a week ago. PayPal support is mostly unhelpful.
A workaround purported in the community forum is to start collecting a shipping address, and set the shipping rate to 0.00.
[1]: https://www.paypal-community.com/t5/PayPal-Payments-Standard/Complete-Purchase-Button-failing/td-p/3073625
I reported the issue via Merchant Technical Support on the 22nd and got this response yesterday:
"Unfortunately, the problem you're experiencing appears to be caused by technical issues within the PayPal system.
I added this account to our existing engineering ticket so that when the problem is resolved, you will be notified of its completion right away.
Our engineers are already working diligently on a solution to this problem. This ticket will remain in a "Pending Fix" status until you're contacted about the resolution.
I apologize for the inconvenience and thank you for your patience!"