I see this error when a form is submitted:
Fatal error: Cannot use object of type MB_Frontend_Post as array in /home/tomw3375/public_html/myuni/wp-content/themes/myuni-theme/assets/metabox/extra/_meta-extra.php on line 12
But when i login to the backend of wordpress the post has been added.
For an example of the error please feel free to log in:
Once logged in you'll see a "add New" tab, click this to submit a new post.
my metabox template looks like this: