Under the Settings > Utilities, we need to add a tool to reset the permissions of the shares to what they should be. If you use the USB > NAS option to get files onto the EX4, then move those files where they go, the permissions are all messed up. These permissions are responsible for the other forum posts that talk about being unable to remove directories and such. You can also have permission problems if you move files from one share to another with differing permissions.
Please add a tool to go through and reset the permissions on each share. It’s only a single unix command to it, per share.