SED/Paya integration seems to have failed


All of the sudden, SED/Paya will no longer launch and we don't have access to the Vault or CC Payment processing.

Even Maintain Credit Card Processor Accounts -> Test Account fails.  Has anybody seen anything like this before?  I'd guess that the integration between Sage 500 (2016, and SED is broken somehow, but not sure where else to go from there.

Weirdly, I've seen this on 2 remote machines (that connect over VPN), and also our RDS server. So, this suggests that it's site-wide, somehow.