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

You need to create a system.net log for your app. You will need to create a myapp.exe.config config file and put the following into it.

<?xml version="1.0" encoding="UTF-8"?>

<configuration>
    <system.diagnostics>
        <trace autoflush="true" />
        <sources>
            <source name="System.Net">
                <listeners>
                    <add name="System.Net" />
                </listeners>
            </source>
            <source name="System.Net.Sockets">
                <listeners>
                    <add name="System.Net" />
                </listeners>
            </source>
            <source name="System.Net.Cache">
                <listeners>
                    <add name="System.Net" />
                </listeners>
            </source>
        </sources>
        <sharedListeners>
            <add
                name="System.Net"
                type="System.Diagnostics.TextWriterTraceListener"
                initializeData="System.Net.trace.log"
            />
        </sharedListeners>
        <switches>
            <add name="System.Net" value="Verbose" />
            <add name="System.Net.Sockets" value="Verbose" />
            <add name="System.Net.Cache" value="Verbose" />
        </switches>
    </system.diagnostics>
</configuration>

If you run with this config file, it will create a logfile called system.net.trace.log. That file will have more details on why this is failing.