IE and Edge are ignoring application/octet-stream MIME Type - apache

Question

Recently I've created a subdomain for downloads and I want the browser to download files instead of viewing it. For this I've added the following line into the .htaccess file:
AddType application/octet-stream .txt .png .jpg .jpeg .gif .exe .zip .rar .gz .sh .bat .doc .docx
On Firefox and Google Chrome it works but both Microsoft browser - Internet Explorer and Microsoft Edge are ignoring the MIME-Type and viewing them instead. How I also can force them to also download the files?

Answer 1

I can see that you had added all the file types in single line. So you can try to add them in separate line to check whether it solves your issue or not.
Based on my search, I find that IE can work with code below. So you can also make a test with it.
# Force PDF Download instead of display
<FilesMatch "\.pdf$">
ForceType applicaton/octet-stream
Header set Content-Disposition attachment
</FilesMatch>
## End Force PDF Download instead of display
Reference:
Forcing a file to download in a browser via htaccess
If you are using PHP than you can try to refer approach below.
PHP allows you to change the HTTP headers of files that you’re writing, so that you can force a file to be downloaded that normally the browser would load in the same window. This is perfect for files like PDFs, document files, images, and video that you want your customers to download rather than read online. Using PHP you can take advantage of the PHP built-in readfile function:
$file_url = 'http://www.example.com/file.pdf';
header('Content-Type: application/octet-stream');
header("Content-Transfer-Encoding: Binary");
header("Content-disposition: attachment; filename=\"" . basename($file_url) . "\"");
readfile($file_url);
exit();
Reference:
(1) Force Files to Download and Not Open in Browser Using Apache or PHP
(2) Force save files all browsers - not open in browser window