The request was aborted: Could not create SSL/TLS secure channel

Question

We are unable to connect to an HTTPS server using WebRequest because of this error message:

The request was aborted: Could not create SSL/TLS secur

Answer 1

The approach with setting

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12

Seems to be okay, because Tls1.2 is latest version of secure protocol. But I decided to look deeper and answer do we really need to hardcode it.

Specs: Windows Server 2012R2 x64.

From the internet there is told that .NetFramework 4.6+ must use Tls1.2 by default. But when I updated my project to 4.6 nothing happened. I have found some info that tells I need manually do some changes to enable Tls1.2 by default

https://support.microsoft.com/en-in/help/3140245/update-to-enable-tls-1-1-and-tls-1-2-as-default-secure-protocols-in-wi

But proposed windows update doesnt work for R2 version

But what helped me is adding 2 values to registry. You can use next PS script so they will be added automatically

Set-ItemProperty -Path 'HKLM:\SOFTWARE\Wow6432Node\Microsoft\.NetFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -Type DWord
Set-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\.NetFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -Type DWord

That is kind of what I was looking for. But still I cant answer on question why NetFramework 4.6+ doesn't set this ...Protocol value automatically?