Hey, a site that I look after has been having EXACTLY the same problem, he is running v7.9.4. I haven’t found a fix for him, however, on other EARLIER versions of Suite when this has happened I have set ALL file/folder permissions to 777, run an Admin Quick repair and rebuild and then reset file/folder permissions to the accepted Suite defaults and it has created the menu listing
On the LTS version 7.8.7 I have implemented this type of custom menu link multiple times WITHOUT a problem, although now and again it has required an Admin Repair/rebuild
Thanks all, I’ve resolved this. There is a another file being generated under custom\module. Just added button line of code under modules{case}\metadata\detailviewdefs.php will do.