You are able to get groups working, if you adjust line 164 like this (Don’t use the inbuild plugin editor!):
Original:
$text = str_replace('%LAST_NAME%', get_post_meta($o->ID, '', true), $text);
Modified:
$text = str_replace('%LAST_NAME%', strval(get_post_meta($o->ID, '', true)), $text);
get_post_meta() has a mixed output, but str_replace() expects a string. So you need to convert it to string before with strval().
I hope that’s fine for all cases. I’m a developer, but not familiar with PHP and I may miss something here….
