To me this seems like a bug. I get this error after I update a page and then go to view that page. If I refresh again I don’t get the error.
The problem seems to be that $pttimestamp_old
can get set to an empty string which still returns true at the isset if statement:
//
// /wp-content/plugins/schema/includes/json/schema-output.php on line 43
//
if ( isset($pttimestamp_old) ) {
$time_diff = $pttimestamp - $pttimestamp_old;
if ( $time_diff <= DAY_IN_SECONDS ) {
$json = get_post_meta( $post->ID, '_schema_json', true );
} else {
delete_post_meta( $post->ID, '_schema_json' );
$json = array();
}
}
changing isset
to !empty
should make the error go away but hopefully the devs will come up with a fix in a future release.