I tried clicking on the 't' checkbox on Component.GetComponentInChildren(Type). The graph went blank, and the console spammed errors - which I can't copypaste because, subsequently, when opening a new graph, I'm stuck with a green noodle from nowhere, and the console spamming null reference errors preventing me from scrolling up.

I've uploaded the project at https://www.dropbox.com/s/sojh8pammr1nafm/udonsandbox-brokencheckbox.7z?dl=0 - the initially broken graph is the "Shuffle udon program graph" asset.