"File not found." PHP issues with IDN after update?

[Towy]

Issue Summary:

After performing a sudo apt update and sudo apt upgrade, some of my WordPress sites with internationalized domain names (IDNs) containing special characters (like “Ø”) started returning a “File not found” error when trying to access /wp-admin or any PHP files. This issue is specific to the IDN domains, while other domains without special characters continue to function normally.

Error Log:

[Fri Aug 09 12:45:53.431012 2024] [proxy_fcgi:error] [pid 30534:tid 30578] [client IP:0] AH01071: Got error 'Primary script unknown', referer: https://domain.com/wp-admin/

Troubleshooting:

I’ve confirmed that the problem is not related to any other domain, or is of another cause. The problem only affects the domains with special characters in their names.

[Towy]

(Deleted comment) Added to post.

[Towy]

@eris Any chance you could pitch in? My relative’s sites are down and I was hoping to fix this within a few hours.

[Aartsie]

Can you place a info.php file in the public_html folder with in it:

<?php
phpinfo();

And check if you can reach this in the browser.
Or if you can run it from the commandline?

[eris]

I don’t know what the issue is. I had the same issue on tet server but can’t replicate on a different one

[Towy]

I tried that already, does not work.

Running from CMD works.

[Aartsie]

@Towy

Primary script unknown

On the internet i read things about .htaccess file. Can you check that one if it is different with a working one? Or maybe you can share it here?

And i read some things about adding:
ProxyErrorOverride on

In the apache config when you are using the apache+nginx config.

[Towy]

Yeah I made sure to play around with .htaccess, and I am certain it is not the cause.

When adding ProxyErrorOverride on this happens instead:

[Towy]

I hope someone with some ideas can pitch in soon

[Towy]

I also tried adding a new subdomain of one of the IDN’s and made a fresh installation of WordPress, it also did not work. So the issue is 100% isolated to just IDN’s.
Google and ChatGPT is sadly not of much help this time…

[eris]

What OS are you using?

[Towy]

Ubuntu 22.04.4

[Towy]

A temporary fix I found is to delete the domain, and then add it back as punycode. It’s like if the folder is using special characters it doesn’t want to load its PHP files properly. It’d be nice to have a permanent fix though.