devtools-render-failed

[wizzard] the graph could not be drawn: <message>. A layout override or a flow shape the
renderer has not seen threw; the wizard, the strip, State and Activity are unaffected. Remove
the layout prop to use the built-in layout, or record a session and attach it to an issue.
…/errors/devtools-render-failed

Shown by the Graph tab in place of the graph. It is an error boundary around the renderer alone, so the diagnostic strip, the State tab, the Activity tab and the export keep working; a graph that cannot be drawn is not a reason to lose the refusal that was being diagnosed. The same line goes to the console, followed by the thrown error and the React component stack, which names the component that threw.

Two causes, in order of likelihood. A layout prop that threw or returned something the renderer cannot read: the built-in layoutGraph is the way to confirm it, since removing the prop restores the drawing. Or a flow shape the renderer has not met - a node kind, an edge target or a when expression from a newer core than the installed devtools.