This is an odd recurring problem:
Suddenly, users were not able to make any changes to Excel documents on the root of a specific network drive. They would get a "Document not saved." error. So, I investigated further and found that no new documents or folders could be created successfully on the root of the drive. When trying to create a new folder (or text document, for that matter) and name it, I receive an error saying, "The action can't be completed because the file is open in another program. Close the file and try again." So, for some reason the server sees every new file that is created as if it is already being accessed elsewhere. It doesn't matter which user creates the folder/file or from what computer (either directly on the server or over the network from a desktop).
I can copy one of the already existing documents from the root of the network drive to a local desktop, make changes, save the document and copy it back to the network drive and overwrite the old version. This is too tedious.
To make things stranger, I can do anything I want within any of the subfolders on the network drive, just not on the root of that drive. This is my solution so far: to create a new folder on the desktop of the server, name it, copy it to the network drive and put all files that reside on the root of the drive in that folder, and then everyone can access and edit those files. No other network drives have this problem.
The permissions of the root folder and the subfolders are nearly identical - Users, Administrators, Domain Admins all have Full Control.
On Friday, 8/1/2014, I installed the latest updates for the server and rebooted it. The problem disappeared. Now, on Monday, 8/4/2014, the problem is back.
I have no idea what is causing this. Any suggestions??