Steps to reproduce:
* Browse to a EUR/NL payment page, such as https://payments.wikimedia.org/index.php/Special:GlobalCollectGateway?title=Special%3AGlobalCollectGateway&appeal=JimmyQuote&ffname=rtbt-ideal&uselang=en&language=en¤cy=EUR&country=NL
* Select a bank, try "ABN"
* Fill your your info
* Click Continue
This should either redirect you to a bank or present an error. However, we see that the backend is getting a "430900 - no valid provider" error, but the frontend simply refreshes as if nothing is wrong. Instead, we should present an error and also log something loud so that we know the bank is down.