We have several users accessing the same Excel files through an SMB network share. Previously, when one user opened a workbook for editing, anyone else who opened it would be warned that the file was being edited and could either wait, ask the other user to close it, or create a copy. That warning stopped appearing about six months ago. A second user can now open the workbook without seeing any indication that someone else already has it open. The files are stored on a local network share, and we are using Office 2019, build 10417.20197. I have found plenty of information about files incorrectly remaining locked, but not much about Excel failing to show the lock notification at all. Could this be caused by an SMB, Group Policy, antivirus, or Excel configuration change?
4 Answers
Also confirm that everyone is reaching the same physical files through the same path. If DFS or another replication layer is involved and users are being sent to different copies, each Excel instance may only see its own server's lock state. Testing with a direct UNC path to the file server can help rule that out.
Make sure the workbooks have not been switched to Excel's newer shared-workbook or collaboration behavior. Automatic saving and collaborative editing can make multiple users appear to be working in the same file rather than producing the old read-only warning. In the legacy shared-workbook settings, check whether the option to use the older document-sharing method is enabled if that is the behavior you need.
Excel normally uses a hidden owner file with a name beginning with ~$ to track who has a workbook open. Check whether something is deleting those files, such as antivirus or endpoint security software. Also verify the SMB server settings, especially leasing and opportunistic locking, since disabling them can affect how file-open information is handed off between clients.
A Group Policy drive-map change could explain why this started happening suddenly. If the drive is mapped using Replace instead of Update, every policy refresh can disconnect and remap it. That can invalidate the original file handle and leave Excel unaware that another user still has the workbook open. Changing the mapping to Update is worth checking, along with any recent GPO or security-software changes.
I checked the shared-workbook settings, and the option to use the old method for shared document handling is not enabled. The Office installation is still Excel 2019, build 10417.20197.