Multi-site 404 redirect in wp-admin non-index php files

Hello,

I’ve been literally on this for over 8+ hours now trying to fix it, here is my problem.

I manage a WordPresss website on a VPS (cPanel) which is setup as a multi-site, it has 4 different multi-sites.

They all work on the front-end and always have but suddenly over night, without any clear cause, the dashboards of the multi-site (not the parent site) started having issues.

All WordPress .php files in a child website, for example: https://www.website.com/child/wp-admin/options-general.php will return a 404 error even though I am logged in in a superadmin account.

The same thing applies to all /child/wp-admin/*.php files and for ALL children on de network.

Stuff that I tried

1. Disabling all plugins and resetting all themes of subsite to default theme
2. Recovering an old database from where it was known to work
3. Manually adding a .php and .html file to the wp-admin folder to see if they exist from the child path, the .html file works, php doesn’t.
4. Multiple PHP versions, 7.1, 7.2 and 7.0 and 5.6
5. Recovering old files from where it was know to work.
6. Disabling / updating nginx, cPanel, restarting the server
7. Nothing seem to have done a dent, there are no major php errors only the usual notices

https://www.mydoo.nl/dierenbranche/wp-admin/test.html
https://www.mydoo.nl/dierenbranche/wp-admin/test.php

I’ve tried disabling NGIX, switched to other PHP versions (default is 7.1, tried 7.2 and 5.6, no difference), I tried multiple variations of my .htaccess files and tried updating to the newest WordPress, right now it’s 4.7.2,

I hope someone can help me possibly point into the right direction on this!

• This topic was modified 6 years, 4 months ago by wmisiedjan.

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