Box Sync 4.0 provides detailed user notifications if there an issue syncing a file or folder.
Box Sync does not allow folder moves if the folder owner has changed on Box. For example, if you try to move a collaborative folder into your root directory, you will be converting the folder ownership to be private.
All devices with Box Sync installed.
First move the folder back in your local computer. Next, on the Box web site, try to move the folder to the required location.