There's another community post with 404 debugging tips that might be helpful. Please give these solutions a try and let us know how it goes.

https://community.vercel.com/t/debugging-404-errors/437

A human should be around soon to offer more advice. But you can also get helpful information quickly by asking v0.

If the Output doesn't have an index, that explains the 404. Now we need to figure out why the output doesn't match what you expected.

Do you have a public repo or minimal reproducible example that you can share so we can help debug? Or a description of the project settings and framework used?

The tips linked above can help if you prefer to DIY