Why duplicate excel files are created when saving a shared file

Question

We have an excel file on a shared(network) drive. This excel is being used (Updated and modified) by multiple team members across the globe. We have the shared option set for this file (Image below).

Along with the users, this file is accessed and edited by a c# program as well. However occasionally the c# program throws below error message.

\\shared\location\testfile.xlsx is read only and can not be overwritten.
It has been saved as file \\shared\location\testfile (n).xlsx

Where (n) keeps on increasing and duplicate of this file is created. example below.

\\shared\location\testfile (1).xlsx
\\shared\location\testfile (2).xlsx
\\shared\location\testfile (3).xlsx
.....
\\shared\location\testfile (n).xlsx

We are not able to figure out under which scenario this issue occurs. Did anyone face this issue? can you tell us how to resolve this issue or at least how to reproduce this issue.

Answer 1

The legacy Shared Workbook feature has always been buggy and impossible to troubleshoot. Problems with that feature can arise at any time, and often are not reproducible on other computers or environments.

Therefore, the best advice for many years before the new Co-Authoring was introduced with Office 365 and online locations, was to avoid the Shared Workbook feature like the plague.

From your screenshot it is apparent that you are using Office 365. The best solution for this scenario will be to move the file off the file share and store the workbook in a location that supports the modern co-authoring and forget about the legacy Shared Workbook feature.