We have several users accessing the same Excel files through an SMB share. Previously, if User A opened a workbook for editing, User B would receive a warning that the file was being edited and could either ask User A to close it or create a copy. About six months ago, that behavior stopped. User B can now open the workbook without seeing any warning while User A is still editing it. Most troubleshooting articles I've found deal with files incorrectly appearing locked, which is the opposite of our problem. We're using Office 2019, build 10417.20197. Could this be caused by an Excel setting, SMB configuration, a group policy, antivirus software, or something else?
4 Answers
Also verify that the workbooks haven’t been moved into a collaboration mode or are being accessed through different paths. If DFS Replication is involved, users reaching different server copies may not see each other’s locks. Test by having both users open the file through the exact same server and share path.
Excel 2019 can use older shared-workbook behavior, so check the shared-workbook settings as well. If automatic saving or a collaboration feature is enabled, Excel may allow simultaneous editing instead of presenting the traditional read-only/ create-a-copy warning. However, for a normal SMB share, the server, drive mapping, and security software are more likely causes.
A drive-mapping policy could explain the timing. If the mapped drive is configured with Group Policy Preferences using the Replace action, each policy refresh disconnects and remaps it. That can kill the original file handle and leave Excel’s lock state stale even though the workbook is still open. Changing the mapping action from Replace to Update may resolve it.
That’s a good lead because the behavior started around the time some policies changed. I’ll check the drive-mapping settings and look for evidence that the hidden lock files are being removed.
The lock depends partly on Excel’s hidden owner file, usually named something like ~$filename.xlsx. Check whether antivirus or endpoint security is deleting those files. It’s also worth checking the file server with Get-SmbServerConfiguration, especially EnableLeasing and EnableOplocks. If either is disabled, SMB locking behavior may not work as expected.
I checked the shared-workbook options, and the setting for using the old document-sharing method is not enabled. The files are stored on the SMB share, so I’ll investigate the server and policy side next.