WP + Discourse; New User SSO not working

[pearsonified]

Hoping y’all can help me with a little issue here…

I’ve set up WP Discourse and Discourse, and everything looks good.

However, I had a customer sign up (on the WordPress side of things) before Discourse was connected, and that user was NOT created simultaneously in Discourse.

When this user tries to visit the forums, he is redirected to my primary domain with a long SSO query string appended to the URL.

(In other words, it doesn’t work.)

I’ve chosen to bypass email verification to remove that potential obstacle, so that’s not the issue here.

I’ve also selected sync user data in the WP Discourse Plugin in hopes that this might resolve the issue, but it did not.

I feel like I might be able to manually resolve this if I can create a user inside Discourse, but I can’t see a way to do that based on the way my forums are currently set up.

So what can I do? If possible, I would prefer not to tell this user to cancel their payment and then do the whole thing over again…

Thank you for any insight you can provide!

[pearsonified]

Update: I was impatient and made the user re-purchase. Unfortunately, we ended up at the same result—SSO does not work, and instead of reaching the forums, the user is sent back to my primary website with a large SSO query string appended to the URL.

What do I need to do to resolve this?

[pearsonified]

I figured out the problem:

The secret keys did not match. For some reason, I thought Discourse offered me a base64 version of the text I entered into the secret key field (when copying the key to paste into WordPress), but this is not the case—the keys must match identically.