Authentication fails

On the plugin settings page, I click “Log in and get my Access Token”.

I select I want to show a ‘Facebook page’ and press ‘Continue’.

I am required to login to Facebook and do so.

A Facebook dialogue shows, saying “Something went wrong”, with the only link being for “Return home”.

I click “Return home” and then the ‘Back’ button in my browser. This results in me seeing the authorisation dialogue that starts with “Smash Balloon WordPress will receive your name and profile picture….”.

I press “Continue as {{my name}}” and then select a few pages, then I click “Next”.

Next the radio button allowing Smashballoon to manage my selected page is checked and I click ‘Done’.

The next dialogue tells me that “You’ve now linked Smash Balloon WordPress to Facebook”. I press ‘Ok’ and am returned to the settings page for the plugin in my WordPress installation.

I see a dialogue that says I can use the access token for any page, not just the ones I’ve selected. I press the disabled blue button that says something like “Use this token”.

The “Facebook Access Token” field is now green, but empty.

I press “Save settings and clear cache”. After this, the “Facebook Access Token” is no longer green and still empty.

Using the plugin shortcode results in “Unable to display Facebook posts.” Showing the error results in this:

Error: An access token is required to request this resource.
Type: OAuthException
Code: 104
Please refer to our Error Message Reference.

How to make this work?