update.php [continue] url return 404

The steps to reproduce are normal activities so this is probably more of a web server setup issue on your end. For example, update.ph/selection isn't a PHP script, unless that is just a typo. No one is going to be able to assist without more information that only you can provide.

Are you using Apache or Nginx? Having a similar issue with nginx.

dimpalmangrulkar20@gmail.com → made their first commit to this issue’s fork.

Hello @mizage →
I'm using nginx. My configs may be uncomplete?

I think the best-known configuration for nginx is in ✨ Provide documentation/default server block for Nginx server. Needs work . If you are using a different configuration than that you are experimenting.

I know it's confusing, but update.php and the database update UI is a separate component from update.module, which is only the "Update status" module that provides the "Available updates" report at /admin/reports/updates (and in earlier versions of core, the "Update Manager" UI that tried to install available contrib updates on your webserver).