VSTO installs over HTTPS issues

Published on Monday, February 25, 2019

Are Envrionmental?

Test with this setup.exe.

The Problem

Setup runs sucessfully over http, but switch to https by publishing again with the https url or by using setup.exe -url="https://myurl.com/MyAppFolder/setup.exe"

URLDownloadToCacheFile failed with HRESULT '-2146697208'
Error: An error occurred trying to download 'https://myurl.com/MyAppFolder/setup.exe'.

Other Examples

https://stackoverflow.com/questions/20244507/download-clickonce-fails-from-setup-exe

Solution

As explained on technet [https://social.technet.microsoft.com/Forums/ie/en-US/3d443283-c251-44b8-99ab-7ee33c928eee/group-policy-setting-blocking-downloads-from-https-even-on-trusted-sites?forum=ieitprocurrentver](Check the GPO) the GPO was under:

User Configuration\Policies\Administrative Templates\Windows Components\Internet Explorer\Internet Control Panel\Security Pages\Advanced Page\Do not save encrypted pages to disk

or

User Configuration\Policies\Administrative Templates\Windows Components\Internet Explorer\Internet Control Panel\Advanced Page\Do not save encrypted pages to disk

Group Policy Management Editor

By default this value is not configured Do Not Save Encrypted File To Disc Dialog

In Internet Explorer the associated configuration option is found in Internet Options on the Advanced tab. Do Not Save Encrypted File To Disc Dialog