Hi, in short: we had a similar problem with image set to inactive. Do you remember?
Reason was a enum field in the database which expected a string instead of a number.
Solution.
One change at field active: \''.$image['active'].'\' in save_item.php line 681
original:.'VALUES ('.(int)$item_id.', \''.$image['filename'].'\', '.$image['active'].', '.$image['position'].', \''.$image['alt'].'\', \''.$image['title'].'\', \''.$image['caption'].'\')');
replace with.'VALUES ('.(int)$item_id.', \''.$image['filename'].'\', \''.$image['active'].'\', '.$image['position'].', \''.$image['alt'].'\', \''.$image['title'].'\', \''.$image['caption'].'\')');