Purpleair returning 500 Error - was working for many months

Again, this API has been working for almost year without a problem - why now?

Below is the Error I am getting in the logs:

Error has been observed at the following site(s):
*__checkpoint ⇢ 500 INTERNAL_SERVER_ERROR from GET https://www.purpleair.com/widget.json [DefaultWebClient]
Original Stack Trace: