Issue is occurring due to disabling of the TLS 1.0

Question

I have observed TLS/SSL secure channel issue with provide hosted app while testing the application(XLCubedViewer). The issue is occurring due to disabling of the TLS 1.0.

"error is: at System.Net.HttpWebRequest.GetResponse() at Microsoft.SharePoint.Client.SPWebRequestExecutor.Execute() at Microsoft.SharePoint.Client.ClientRequest.ExecuteQueryToServer(ChunkStringBuilder sb) at Henkel.XLCubedReportsWeb.Controllers.HomeController.GetDefaultImageLinkUrl(String tileID)
The underlying connection was closed: An unexpected error occurred on a send"

Is there any out of the box solution (without any application code change) which can tell application to connect to the default TLS protocol???

Answer 1

Hello @Ava Tomlinson ,

There is no out of the box solution (without any application code change) that can tell the application to connect to the default TLS protocol.

Please add this to beginning of your code:

ServicePointManager.SecurityProtocol |= SecurityProtocolType.Tls12;  

Here is a case for your reference：

• The underlying connection was closed sharepoint online executequery

It is worth noting that disabling TLS 1.0 may cause compatibility issues with sites that don't support newer security protocol versions.

If you add this code, you still get an error. Then I suggest you still enable TLS 1.0 .

Thanks,
Echo Du

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