Hi everyone.
I am no PHP expert, but it appears on line 154 when $body[‘o:tag’] is referenced, $body[‘o:tag’] is in fact undefined. Which is why what Phil said ‘worked’. However, preventing that entire body from executing could cause problems. A better workaround, I think, would be to provide the default option that line 154 wants, which is when $body[‘o:tag’] is equal to ” rather than being undefined.
In short, go to lines 146-149 and change
if ( isset( $mailgun['tag'] ) ){
$tags = explode(",", str_replace(" ","", $mailgun['tag']));
$body['o:tag'] = $tags;
}
to
if ( isset( $mailgun['tag'] ) ){
$tags = explode(",", str_replace(" ","", $mailgun['tag']));
$body['o:tag'] = $tags;
} else {
$body['o:tag'] = '';
}
This makes sure that $body[‘o:tag’] always has a value and will not be undefined when it is referenced. Hopefully this helps!