wordpress 404 error after update

[fredricksoncr]

All of my wordpress sites are having a 404 error after updating to 6.3 when attempting to log in to the back end.

i have tried multiple sites, i have turned off all plugins, i have reset to base themes, i have manually performed the update by copying the files. this new update is borked.

the site in main question is chicagolandhomeproducts.com

[jrf]

@fredricksoncr Unless this happens for everyone, this is not critical. I do understand you are frustrated, but please respect the ticket classifications used in this project.

[fredricksoncr]

well i can link several other boards and tickets that are all experiencing the same issue.

and 20 websites is nothing to sneeze at. this is very clearly a major issue within wordpress its self

​https://wordpress.org/support/topic/upgrade-php-is-404-after-update-to-6-3/#post-16964091

it also looks like all the recent tickets are about this update messing up sites....

[Sfdsfwer]

Same problem here, with over 200 customer instances (version 6.3 and 6.3.1).
This is definitely not a "minor" bug. We have a mess of work with it.

[ozgursar]

Reproduction Report

Description

This report validates whether the issue can be reproduced.

Environment

• WordPress: 6.9
• PHP: 8.3.29
• Server: PHP.wasm
• Database: WP_SQLite_Driver (Server: 8.0.38 / Client: 3.51.0)
• Browser: Chrome 143.0.0.0
• OS: macOS
• Theme: Twenty Twenty-Three 1.1
• MU Plugins: None activated
• Plugins:
  • Test Reports 1.2.1

Actual Results

Tested upgrading from 6.2.1 to 6.9 and 404 issue didn't happened.

Additional Notes

Found a solution in one of the wordpress.org support threads mentioned by @adatosystems
​https://wordpress.org/support/topic/upgrade-php-is-404-after-update-to-6-3/

Suggested solution (which I can't replicate at this point):

1- Open the "wp_options" table using phpmyadmin
2- Find the “db_version” record and note the "option_value"
3- Using file manager of your control panel or FTP, make a copy of /wp_includes/version.php
4- Edit version.php and change the line for "$wp_db_version=" to match the version found in the database
5- Try accessing the WordPress dashboard via /wp-admin/ again and re-try the upgrades.