ID 221267 - VectorBlur2 can't use rgb input and errors saying missing rgba data

Problem summary
VectorBlur2 node errors if it only has an RGB input. It says Input is missing rgba

Customer reported version
nuke.10.0v1

Customer reported platform
centos6

Steps to reproduce

1) Open the attached Nuke script, and the error will be visible

2) If you enable the Shuffle node, the issue is solved

The original VectorBlur node has no issues with using just rgb data.

Reproduced by support
The problem has been reproduced on: 

Nuke 10.0v3 - Windows 10 - MacOSX 10.11

Nuke 10.0v1 - Windows 10 - MacOSX 10.11 

The VectorBlur2 node was introduced in Nuke 10.0v1 so could not test older versions of Nuke.

Expected behaviour
For the vectorblur2 node to be able to use rgb input

Actual behaviour
It errors, asking for rgba data.