ID 476430 - [Cryptomatte] Blender cryptomatte files not importing into Nuke

Problem summary
At the release of Nuke 13, we implemented our own native version of the popular Cryptomatte tool.

It has recently been discovered that there is an issue when using exr files rendered from Blender, that contain Cryptomatte layers. While the exr files import correctly, it appears that the layers are not selectable through Nuke's new native Cryptomatte plugin.

Customer reported version
nuke.13.0v2

Customer reported platform
windows10

Steps to reproduce
1) Open a new Nuke 13 session
2) Read in an exr rendered file from Blender that contains Cryptomatte layers (or use attached file)
3) Create a Cryptomatte node to interpret the Cryptomatte data
Result: Layer selection does not contain the expected layer, and unable to pick a colour to use as a matte.

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Expected behaviour
Layer selection should be selectable and Picker functional

Actual behaviour
As the layer is not loaded into the layer selection, the Picker will not work correctly

Workaround
Through researching into the issue, it appears the cause is related to spaces created within the metadata naming convention provided by Blender, and Nuke's inability to understand these spaces. This occurs specifically within the Cryptomatte layer name prefix 'View Layer', and once the gap is replaced with an underscore, this resolves the issue. e.g. 'View_Layer'

This alteration can be achieved in comp by creating a ModifyMetaData node between the Read node and the Cryptomatte node, then replacing the space with an underscore for the Cryptomatte's metadata name attribute using the set action.

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Reproduced by support
This bug has been reproduced in:
Nuke 13.0v2 - Windows 10 - MacOS 10.15.6 - CentOS 7
Nuke 13.0v1 - Windows 10 - MacOS 10.15.6 - CentOS 7

Unable to reproduce bug in:
Nuke 12.2v6 - Windows 10 - MacOS 10.15.6 - CentOS 7

Earliest version tested
Nuke 12.2v6
- The native Cryptomatte tool did not exist in Nuke before Nuke 13 releases.