After purchasing an item using guest checkout, there's an option to quickly create an account on the order success page. On choosing to create an account, there seems to be some sort of error - I can see a warning/alert icon and the div background turns red but there's no error message/text.
I'm not sure if this text is getting accidentally hidden by some CSS and I'm unable to find the error message strings in any of the Magento files.
Since there is no user input at this stage, and the email address has already been validated during checkout, I'm not sure what kind of error could come up at this stage.
How do I find out what the error is without the error text?