Protobuild fails to generate

I'm running Window. After cloning the project, and running Protobuild.exe --generate in the repository base directory, the generation process hangs whenever it tries to grab this external resource in particular.

(5/10) HTTPS GET https://api.github.com/repos/Protobuild/Protobuild.SWIG/branches/master
Exception during web request:
System.Net.WebException: The request was aborted: Could not create SSL/TLS secure channel.
   at System.Net.WebClient.DownloadDataInternal(Uri address, WebRequest& request)
   at System.Net.WebClient.DownloadString(Uri address)
   at Protobuild.RetryableWebClient.PerformRetryableRequest[T](String message, Uri baseUri, Func`2 func)
Backing off web requests for 1600ms...

I've also been having a similar error when trying to install the Protobuild Manager (It repeatedly fails to create an SSL/TLS channel).