I recently enabled Preferences>Checkout & Payment>Customer Checkout Settings>Guest checkout with optional sign-in
The problem is that if a customer actually tries to create an account (and they've previously purchased something from us before the customer registration feature was enabled) they get an error message of "Email has already been taken". Presumably this is because their email account already exists in our customer records but they have not yet created an actual customer account.
Aside from being confusing, this prevents our loyal customers from being able to create an account.
Is there a workaround or other way to deal with this?
I am also having this same problem and would love some feedback on what I need to do to fix this. I recently added a "gift card" feature and in order for customers to see how much they have left on their cards, they need to be able to login. But if they've already ordered from us before the Customer Registration settings were activated, then they're "email has already been taken". Kind of obnoxious. Any help would be most appreciated.
I found a little bit of a work-around for any of you that are interested:
I've copy and pasted below the pertinent information for our questions, but here's the link to the entire article on the Shopify wiki:
To create an account for an existing customer:
Once an account is active, the customer will be able to use their email/password to log in when they encounter the customer login screen during checkout.