Publishing an iOS build from Visual Studio fails

Question

I'm trying to publish my application from Visual Studio on Windows to TestFlight. When I try to push the file from visual studio I get the error:
"altool" exited with code 1.

Looking in the logs I see the following:

Begining distribution, 2020-12-02 3:41:57 PM
Channel: App Store
App Bundle Id: com.company.app, Version: 0.1
Publishing to 'C:\SDK\2020-12-02\MyApp.iOS 12-02-20 3.17 PM.xcarchive\Published\MyApp0.1.ipa'
The underlying client has been disconnected by the remote host
The underlying client has been disconnected by the remote host
An error occurred while registering a handler for 'ClientStatusMessage' messages, so all the content sent to the topic 'xma/client-status' will not be handled in this active connection
An error occurred while registering a handler for 'PingMessage' messages, so all the content sent to the topic 'xma/ping/{ClientId}' will not be handled in this active connection
Validating bundle...
Uploading 'C:\SDK\2020-12-02\MyApp.iOS 12-02-20 3.17 PM.xcarchive\Published\MyApp0.1.ipa'
The underlying client has been disconnected by the remote host
The underlying client has been disconnected by the remote host
An error occurred while registering a handler for 'AgentStatusMessage' messages, so all the content sent to the topic 'xma/agent-status' will not be handled in this active connection
An error occurred while registering a handler for 'ClientStatusMessage' messages, so all the content sent to the topic 'xma/client-status' will not be handled in this active connection
An error occurred while registering a handler for 'PingMessage' messages, so all the content sent to the topic 'xma/ping/{ClientId}' will not be handled in this active connection
Failed to upload MyApp bundle to the App Store
"altool" exited with code 1.

Publishing project 'MyApp' completed with errors.
Failed to upload MyApp bundle to the App Store
"altool" exited with code 1.

I have no idea what the error code means or how to fix it. Is this a VS bug or is this a configuration error on my part?