How do I force redirect all 404's (or every page, whether invalid or not) to the homepage?

Question

Currently every invalid page is 500 (Internal Server Error) because I probably messed up with my server block configuration.

I decided to shut down my website a whil

Answer 1

Try adding the following line after your index definition:

error_page 404 /index.html;

If that doesn't work, try changing your try_files call to the following instead:

try_files $uri $uri/ /index.html;

Hopefully one of those works for you, I haven't tested either yet.