I have also this fatal error when transaction finish:
Fatal error: Uncaught exception 'Stripe_AuthenticationError' with message 'Invalid API Key provided: ***********************/************+***uXQ=' in
/home/hardannu/public_html/oc-content/plugins/payment/payments/stripe/lib/Stripe/ApiRequestor.php:90 Stack trace: #0
/home/hardannu/public_html/oc-content/plugins/payment/payments/stripe/lib/Stripe/ApiRequestor.php(136): Stripe_ApiRequestor->handleApiError('{? "error": {?...', 401, Array) #1
/home/hardannu/public_html/oc-content/plugins/payment/payments/stripe/lib/Stripe/ApiRequestor.php(74): Stripe_ApiRequestor->_interpretResponse('{? "error": {?...', 401) #2
/home/hardannu/public_html/oc-content/plugins/payment/payments/stripe/lib/Stripe/ApiResource.php(76): Stripe_ApiRequestor->request('post', '/v1/customers', Array) #3
/home/hardannu/public_html/oc-content/plugins/payment/payments/stripe/lib/Stripe/Customer.php(26): Stripe_ApiResource::_scopedCreate('Stripe_Customer', Array, NULL) #4
/home/hardannu/public_html/oc-content/plugins/payment/payments/stripe/StripePayment.ph in
/home/hardannu/public_html/oc-content/plugins/payment/payments/stripe/lib/Stripe/ApiRequestor.php on line 90