MSDeploy: The underlying connection was closed: An unexpected error occurred on a send.

Our company has started deploying all of its numerous web applications via automated (or at least scripted) deployment with MSDeploy. This has worked fine, up until very recently where one machine in particular seemed to be cursed and simply didn't want to work. Even when we nuked the VM and completely recommissioned it from scratch from our VM web server template, we still kept getting the following error:

Error: Could not complete the request to remote agent URL 'https://myserver:10987/MSDeployAgentService'.
Error: The underlying connection was closed: An unexpected error occurred on a send.
Error: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.
Error: An existing connection was forcibly closed by the remote host
Error count: 1.

The problem turned out to be caused by the fact that we hadn't correctly configured the Management Service for MSDeploy (even though we use a custom port for the MsDepSvc deployment service, the Web Management Service (WMSvc) wasn't correctly configured): 

1. Because we were behind a load balancer, we needed to specifically set the IP address of the server
2. We were attempting to use SSL, but we didn't have a certificate specified in the Management Service configuration.

Here's what our configuration looked like in the end, obfuscated to protect the guilty:

Step 1:

Step 2: