Failed to execute 'appendChild' on 'Node': Private field '#if' must be declared in an enclosing class

[michaelmattiolo-calicantus]

I'm new to catalyst.
I created a fresh new project (twice) with no problems.
Once started with pnpm dev I get 1 issue notification from Next. It looks like some handlebars code is injected into a Script section.
Have anybody faced this error?

Here's the error:

Error Type

Runtime SyntaxError

Error Message

Failed to execute 'appendChild' on 'Node': Private field '#if' must be declared in an enclosing class

at eval (components/scripts/scripts.tsx:64:18)
at Array.map (<anonymous>:1:18)
at ScriptManagerScripts (components/scripts/scripts.tsx:63:10)
at RootLayout (app/[locale]/layout.tsx:117:9)

Code Frame

62 | .filter((scriptProps): scriptProps is ComponentProps => scriptProps !== null)
63 | .map((scriptProps) => {
64 | return <Script key={scriptProps.id} {...scriptProps} />;
| ^
65 | })}
66 | </>
67 | );

Next.js version: 15.5.1-canary.4 (Webpack)