We have used Stripe on this account for over a year. A few days ago it stopped working. When in “Live” mode I get this error: “Expired API Key provided: pk_live_T2******************6mgr. Platform access may have been revoked”. When in “Debug” mode I get this error: You did not set a valid publishable key. Call Stripe.setPublishable Key() with your publishable key. For more info, see https://stripe.com/docs/stripe.js“. The website and payments have been working for some time. No new plugins or code have been added.
I registered onto an event on one of your sites and didn’t get an error, if you are still getting the above go to Event Espresso -> Payment methods -> Stripe.
Disconnect your stripe account on the settings there and reconnect again, that should fix the ‘Expired API Key provided’ error.
Note you are also using an the ‘legacy’ integration method (Stripe Checkout) and you may want to switch the ‘Integration Type*’ to ‘Stripe Elements’ on the same setting page as above. Stripe has deprecated Stripe Checkout and whilst it currently still works they have not (and will not be) updated it to support the new SCA regulations.