TypeError in NextJS: <<Container.extend is not a function>>

[Jawisr]

Hi team,
i have just copied the theme.ts into my project and passed to the MantineProvider component, first time I render the page i receive the following error in turbopack:

TypeError: {imported module [project]/nodemodules/.pnpm/@Mantine+core@7.16.1_@mantine[email protected]@19.0.0__@types[email protected]@[email protected][email protected]/nodemodules/@mantine/core/esm/components/Container/Container.mjs [app-rsc] (ecmascript)}.Container.extend is not a function

[project]/app/styles/theme.ts [app-rsc] (ecmascript)

I tried commenting the Container object in the theme but the next component: Checkbox.extend throws the same error.

[Abhishek-S-Lal]

@Jawisr
In the theme.ts file, add "use client" as the first line and it will work as expected.