Internet Explorer 11 on Windows 10 "The file couldn't be downloaded" error message

Hello fellow Experts Exchange members:

I have a Windows 10 Pro PC running Internet Explorer 11 that was reset using the built-in functionality two weeks ago.

After reinstalling updates and applications, everything is working ... except for file downloads in Internet Explorer.

When the user attempts to download *any* file (text file, PDF, executable, Office document e.g. Word/Excel) in Internet Explorer, almost immediately the error message "%Filename% couldn't be downloaded".

Internet Explorer (and Windows) do not display any other details of the error besides that message, and there are no corresponding entries in any of the event logs.

However - and this is REALLY curious - Internet Explorer presents a "Retry" option.  If the user clicks "Retry", the file will be successfully downloaded IN ALL TESTED CASES.

I have checked the following regarding this issue:

• Reset the Internet Explorer browser
• Verified that the "Do not save encrypted pages to disk" security option is NOT checked
• Launched the browser in safe mode with all add-ons disabled

However, even in safe mode, the errors continue to occur.  (And the file downloads are always permitted after the user clicks "Retry".)

Also, I am not sure if the following information is relevant, but when the user clicks on Download links to download text files and Microsoft Excel spreadsheets, the browser does not respond correctly.

As an example, one of the websites has a download button to download text files.  Internet Explorer opens the file download window when the user clicks the download button, but the file has no extension and the file type is "All files".  If the user types ".txt" after the filename, the file is saved correctly (after the Retry button on the error message is clicked); however, if the user tries to save the file as-is, the file is saved (again, after the Retry button is clicked) with no extension (and thus Windows prompts to select the program to open the file when the user double-clicks it to open it).

For another example, a different website has a download button to download Microsoft Excel spreadsheets.  The download link ends in "?download".  The Internet Explorer on the user's computer does not handle this correctly: clicking the Open button will result in a Microsoft Excel error message stating "The file that ends in ?Download couldn't be opened."

I have the user currently using the Google Chrome browser, and the user reports absolutely no issues downloading and opening files with that browser.  Both of the aforementioned websites work correctly: the text files are saved with the correct .txt extension and the Microsoft Excel spreadsheets open without any errors.  (However, the user prefers to use Internet Explorer.)

Have any Experts Exchange members encountered similar problems with Internet Explorer like these before?

I appreciate any assistance!