Preview failure

Previewing my event I see :

A couple of issues with this :

• The icons on the top don’t do anything
• “critical error” shown – I presume this is stopping the actual event text being displayed

Server logs include

AH01071: Got error 'PHP message: PHP Fatal error:  Uncaught Error: Call to a member function get_name() on null in /home/sites/10b/7/79fe0e6b13/public_html/wp-content/plugins/event-bridge-for-activitypub/templates/event-preview.php:1352
Stack trace:
#0 /home/sites/10b/7/79fe0e6b13/public_html/wp-includes/template-loader.php(106): include()
#1 /home/sites/10b/7/79fe0e6b13/public_html/wp-blog-header.php(19): require_once('/home/sites/10b...')
#2 /home/sites/10b/7/79fe0e6b13/public_html/index.php(17): require('/home/sites/10b...')
#3 {main}
  thrown in /home/sites/10b/7/79fe0e6b13/public_html/wp-content/plugins/event-bridge-for-activitypub/templates/event-preview.php on line 1352'

Browser console includes

GET https://u3acommunities.org/event/local-generative-ai/?preview=true&activitypub=true# [HTTP/2 500  1449ms]

Uncaught ReferenceError: openPreviewForApplication is not defined
    onclick https://u3acommunities.org/event/local-generative-ai/?preview=true&activitypub=true#:1