When trying to place a order I get "An error occurred on the server. Please try to place the order again."
In the console I get this:
POST https://www.mydomain.co.uk/rest/default/V1/carts/mine/payment-information 400 (Bad Request)
I use Magento ver 2.1.8 and World Pay as payment gateway. It was working fine in "Test" mode and when switched World Pay to "Live" it gave me that error. Now even when I change back to "Test" it gives me the same error.
Best Answer
You can easily find the actual error by installing the Mage2 Module Experius ExceptionDebugger
But you can also check this manually more information how to debug the checkout manually I would like to referrer you to my codeblog
Let me know if you have any questions!