Allright, I’ve solved the problem.
I needed to activate the “always include” option for JS. Although the “include JS” & “include CSS” options were checked, apparently the third option is required in order to upload files attached to private group posts.
Thanks for your reply.
I have tried to attach PDF, DOCX and simple TXT files.
I do use GD-bbPress-attachments Version 1.9.2. I have checked the settings, they all seem correct.
Strangely, the behaviour of the posting page doesn’t seem to upload the file I’ve selected, e.g. when I attach a file to any post, the uploading time of the page takes a few second (uploading of the file), whereas when I do the same on a private forum, the uploading time is almost instantaneous, as if the file was simple not uploaded
