Node red websocket throwing an error "Missing node type bigsubflow"

I am trying to replicate subflow functionality as it is, I have made few code changes for that. I have created separate type as a "bigsubflow".
I am able to create bigsubflow but while saving it's throwing an error "Flow stopped due to missing node types : bigsubflow"

if anyone is aware about that please help
Attaching error screenshot

Hi - that means the runtime doesn't know anything about the node type bigsubflow.

Without know what changes you've made or how you've tried to copy the subflow functionality its very hard to give you any more advice.

The subflow functionality is not something you can easily replicate in your own node module - a lot of the logic is hardcoded in the core of the runtime.

Can I ask why you are trying to do this? What functionality are you trying to add?

I'm trying to develop separate subflow node, which will not be rendered based on a condition. For instance the inbuilt subflow will be available to one user type but not others, others might have access to the custom subflow-node. Also these custom subflows won't be available to the users who don't have access to this custom node.

What are your thoughts?

Not sure I fully follow what you mean.

There is no support in the editor for different users having different views.

What is special about your custom subflow-node? What functionality does it provide that the built-in subflow doesn't do? Why do you need a different type of subflow?