The below attached registry file once run on your server will enable TLS1.2 and the error for TLS issue will be resolved.

Brief Description:

.NET 4.0 does not enable TLS 1.2 by default.To enable TLS 1.2 by default, it is possible to set the SchUseStrongCrypto DWORD value in the following two registry keys to 1, creating them if they don't exist: 

"HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v4.0.30319" and "HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\.NETFramework\v4.0.30319". 

Those registry keys, however, will enable TLS 1.2 by default in all installed .NET 4.0, 4.5, 4.5.1, and 4.5.2 applications on that system. 

We recommend testing this change before deploying it to your production servers