I am integrating a .NET web application with Salesforce via the Partner WSDL and SOAP API.
I am currently getting an error
UNSUPPORTED_CLIENT: TLS 1.0 has been disabled in this organization. Please use TLS 1.1 or higher when connecting to Salesforce using https.
I know that I can go
Setup > Critical Updates > Deactivate the Require TLS 1.1 or higher
But what is the downside to this? I mean will they stop allowing us to deactivate it at some point?
How can I make my client application use TLS 1.1 or higher?
Edit:
Here is a part of my app.config. The project is a sample Console application just to test integrating with the SOAP API.
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.2" />
</startup>
I found the solution. In my code I set
System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls;
as per https://help.salesforce.com/HTViewSolution?id=000221207