How to add Upload system in new content type?


Active member
Ok, finally i created an AttachmentHandler class for my content type and works, but i dont know why i only can upload 1 file every time i push "Upload File". (Uploader overlay only).

How can i enable multi file upload like when you reply a post, where you can upload multiple files with "Upload file button"?
It's still not working for us, so we would donate 25$ for tutorials with examples for own content types + there attachment & datahandler