On my server I create an xlsx-file and save it to the servers file system. Afterwards the files URL is sent to the clients browser, where the file is supposed to be opened directly in excel with the help of javascript:

window.location.href = 'ms-excel:ofv|u|https://myserver.com/path/to/file.xlsx'

Now the first time it worked like a charm. The file was downloaded, the browser asked whether to open excel, I said yes and the file was opened in excel.

But as as soon as I try to open the file again or another xlsx file in the same way, it stops working. Excel gives a warning, that it could not access the file.

Does anyone have an idea what the reason could be?

• I restarted excel
• I looked for cached files that prevent downloading more xlsx files
• I checked that the files exist and can be opened (accessed them via their urls directly in the browser)