Hi @gavpedz,
Thank you for contacting us! I’ve tested this on a site with PHP 8.0, but I haven’t been able to reproduce the same error so far. Was this the full error message you received or was there possibly any more detailed information that includes the filename and line number of the error? This will help us better investigate the problem.
If not, you could also try using the WordPress debug logs or the plugin Query Monitor to get a more detailed error message we can use to investigate this further.
You could also test going to WordPress Dashboard > Twitter Feed > All Feeds, deleting your current feed, and then clicking Add New and recreating the feed to see if this resolves the problem. After this, you would need to update the shortcode on your page to the shortcode for the new feed.
We’ll wait for your response and look forward to assisting further.
Best regards,
Louis