I think i found the error ??
check the plugin uploads in wp-content/plugins
open includes folder and open the file custom-meta-box.php in your text editor
check line 457 and remove the / before family_data so it looks like
$filename = $dir.'family_data/family_'.$family_id.'.json';
Now create in the family- tree directory a directory and name it family_data
Seems to work now for me.
And yes Qbone…. it seems like it is the chehebar family tree, without the Menu buttons.
While playing around with it I can’t get the relationships connected between both parents and a child, it only connects from the father… seems like we have another problem there.
I hope the author checks the support forums, otherwise someone else might help with that