Not working in 4.2.5 with php 7.1 on the Manage Attachments dialog.
Multiple file upload still works using the image icon on a new post, but from the Manage Attachments dialog, if I look at the console, I see the following error in Chrome.
Same-origin plugin content from
https://myforum.org/forums/clientscr...s/uploader.swf must have a visible size larger than 6 x 6 pixels, or it will be blocked. Invisible content is always blocked.
The message is thrown on the newattachment.php