question

Hi @ubix,

Please use a higher target framework version in your C# project 4.7.2 or higher) to use TLS 1.2 (system default).

Best Regards,

eBay Developer Support

On certain machine we are getting "Could not create SSL/TSS secure channel " but on other it works fine, what could be the issue

Hi. I am also getting this error as of yesterday. I have followed above and have upgraded the .net framework to as above. Also have the azure web app service running at 1.2 TLS and still error. I'm using the .net SDK. any advice?

I am getting this error as of yesterday as yes. Have followed above and web app is running on .net frame work 4.7.2. Have also ensured that azure app service is running 1.2 TLS but still not working

Might only be impacting the API for revising items. We have uploaded new items and removed sold items and that works, but the Revise API call fails.

We are now using TLS 1.3 under .NET 4.8 and are still seeing this.

It does work on some machines. I am not sure what is going on? Any help would be appreciated

Thanks

We added TLS 1.2 to the setting under .NET 4.8 and that worked. So it turns out to be that you need both TLS 1.2 and .NET > 4.7 to make this work. The only failure we saw after that was on a Windows 7 machine that did not have the updates required to support TLS 1.2, and that is solvable by installing said updates.

Hi, I have the same problem.
My project is targeting framework 4.8 but I have "Could not create SSL/TSS secure channel" error

The error is generic and there are many reasons why the SSL/TLS negotiation may fail. ServicePointManager.SecurityProtocol property selects the version of the Secure Sockets Layer (SSL) or Transport Layer Security (TLS) protocol to use for new connections; existing c# socket connections aren't changed. Make sure the ServicePointManager settings are made before the HttpWebRequest is created, else it will not work. Also, you have to enable other security protocol versions to resolve this issue:

ServicePointManager.Expect100Continue = true;
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12
     SecurityProtocolType.Tls
     SecurityProtocolType.Tls11
     SecurityProtocolType.Ssl3;
 
//createing HttpWebRequest after ServicePointManager settings
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://google.com/api/")

If you create HttpWebRequest before the ServicePointManager settings it will fail and shows the error message.