Turbopack Error: Cell CellId { type_id: ValueTypeId { id: 8, name: "turbo-tasks@TODO::::effect::EffectInstance" }, index: 0 } no longer exists in task <DiskFileSystem as FileSystem>::write (no cell of this type exists)

[utomwenimasuen]

Turbopack version: v15.4.5-2-g91e5b6b84
Next.js version: 0.0.0

Error message:

Cell CellId { type_id: ValueTypeId { id: 8, name: "turbo-tasks@TODO::::effect::EffectInstance" }, index: 0 } no longer exists in task <DiskFileSystem as FileSystem>::write (no cell of this type exists)

Debug info:
- Execution of hmr_update_with_issues_operation failed
- Cell CellId { type_id: ValueTypeId { id: 8, name: "turbo-tasks@TODO::::effect::EffectInstance" }, index: 0 } no longer exists in task <DiskFileSystem as FileSystem>::write (no cell of this type exists)

[grilomatheus]

That’s an internal Turbopack crash, often triggered by HMR (Hot Module Replacement) when a file changes during a build.

Quick things to try:

1. Stop the dev server and restart it (next dev --turbopack).
2. Clear .next/ before restarting:

rm -rf .next

3. If it happens consistently after editing a specific file, try isolating the change — it might be hitting a bug in Turbopack’s incremental build.

Since this is an internal error (turbo-tasks effect instance missing), I’d recommend opening an issue with:

• Minimal reproduction repo
• Your OS + Node.js version
• Exact Turbopack + Next.js versions

For now, if you need to keep working, switch to Webpack (next dev) until the fix is merged.