Got this error

[ananya603]

Summary

Failed to write app endpoint /page

Caused by:

• [project]/src/app/globals.css [app-client] (css)
• invalid type: null, expected a string

Debug info:

• Execution of get_written_endpoint_with_issues_operation failed
• Execution of endpoint_write_to_disk failed
• Execution of ::output failed
• Failed to write app endpoint /page
• Execution of *all_asset_paths failed
• Execution of *AppEndpointOutput::output_assets failed
• Execution of AppEndpoint::output failed
• Execution of AppProject::app_module_graphs failed
• Execution of *::additional_entries failed
• Execution of ModuleGraph::from_graphs failed
• Execution of ModuleGraph::create failed
• Execution of SingleModuleGraph::new_with_entries_visited_intern failed
• [project]/src/app/globals.css [app-client] (css)
• Execution of primary_chunkable_referenced_modules failed
• Execution of ::references failed
• Execution of parse_css failed
• Execution of ::content failed
• Execution of PostCssTransformedAsset::process failed
• Execution of evaluate_webpack_loader failed
• invalid type: null, expected a string

Additional information

No response

Example

No response

[jaydubya818]

This is a known Turbopack issue where globals.css is being processed as a client-side CSS module and encounters a null value it cannot stringify.

Here are a few things to try:

1. Clear the Next.js cache

rm -rf .next
npm run dev

2. Check your globals.css for null/empty values
Look for any CSS custom properties or rules that might have an empty or null value, like:

/* Problematic */
--color: ;

3. Try moving the import
Make sure globals.css is only imported in your root layout.tsx, not in any client component.

4. If using @import inside globals.css, try removing those as Turbopack handles CSS imports differently than Webpack.

5. Downgrade to Webpack temporarily by adding to next.config.js:

module.exports = { experimental: { turbo: false } }

or run next dev --no-turbopack

This is tracked as an upstream Turbopack bug — if none of the above work, check the Next.js GitHub issues for your specific error message.