Hard to diagnose Function App issues when service fails to load function

I have a function that loads and executes from the VS 2017 debugger. However, the function fails to load when deployed to the Azure Functions Service.

Via App Insights I can find the follow error message (category-Host.General)

The following 1 functions are in error:
The listener for function 'FunctionName' was unable to start. Microsoft.ServiceBus: An error occurred during communication with 'N/A'. Check the connection information, then retry. Microsoft.ServiceBus: An established connection was aborted by the software in your host machine.

Any insights into how one can root out the cause would be appreciated.

#### Investigative information

Please provide the following:

- Timestamp: 2018-01-18T00:13:03.548Z
- Function App version (1.0 or 2.0-beta):
- Function App name: ID=d9d4b514-0d58-401a-b374-b14dc2dfec4c
- Function name(s) (as appropriate):
- Invocation ID: not available
- Region: EUW

The report names no source file, test, or entry point; begin by reproducing the deployed Function App failure and reviewing the App Insights Host.General message with the supplied timestamp and region. Done means the cause of the Service Bus listener failure is identified and the issue contains concrete diagnostic guidance or a scoped fix.

Written by the indexing model from the issue text.