On fresh Nextcloud installation, everything works fine, when I add mounted VirtualBox shared folder as external hard disk it only shot it but not the content nor the I can upload anything on it. the default user for virtual box media is vbox and I already added www-data to vboxsf group with no chance to work, is there any workaround for this problem?
I would like to say that I am sorry for necroing this topic, but there are several questions like this and not a single answer over the course of several years. So therefore sorry not sorry your documentation on this issue is pretty lacking considering the scale of NextCloud.
There is problem with the way virtualbox mounts the share folder. Adding the www user to the group does not solve the issue. Is it a NTFS problem? I DUNNO!?!?!?!