There doesnt seem to be a way to get around the FileSharing error when a user attempts to upload a file that happens to be open on their own desktop locally (like an Excel file).

Why hasn't Telerik fixed it yet? If so what is the workaround 'cause it ain't built into the control and all the relevant topics deadend with no resolution.

Hi,

In such scenarios we recommend using OnClientFileUploadFailed event, check the error message you are getting and do your custom functionality after that.

I have tested the scenario described with DisablePlugins with .xlsx file opened in the same time in Excel by could not achieve any error. Here is a video of my test and I am attaching a sample web page. Please review them and let me know what else should be made in order to observe the same error and be more helpful?

Greetings,
Plamen
the Telerik team