I can't upload new files to attach them to private messages. I click the Clip icon button to show the Insert an Existing Attachment or Upload a New File drop-down control, then click the Upload New File(s) button inside it:

 2018-07-05_16h47_57.png You have insufficient rights to see the content.

But the drop-down form disappears after clicking the Upload New File(s) button instead of showing the nested dialog to upload new files.

Upgrade to the latest YAF 2.2.4.12 didn't help.

Yes i can confirm the issue, will be fixed in YAF 2.2.4.13