Specifics of your environment

1. Are you acting as SP/IdP/proxy? IdP
2. SimpleSAMLphp: What version are you using? 2.3.1
3. PHP: What version are you using? 8.2.23
4. Platform: unix or Windows? Unix
5. Webserver: Apache/Nginx/ISS? Apache
6. SimpleSAMLphp basedir? /simplesaml/

Describe the bug
The configuration panel of the admin interface used to show check mark symbols for enabled modules and a ban-symbols for disabled ones. In version 2.3.1 the check marks and bans are replaced by Unicode placeholders.

To Reproduce
Steps to reproduce the behavior:

1. Go to the admin panel of simpleSAMLphp
2. Open the configuration panel

Expected behavior
Check marks and ban-symbols should be displayed for enabled/disabled modules.

Screenshots or logs

Additional context
The issue seems to be caused by the admin page not being able to load the Font Awesome font. The browsers developer console shows multiple error messages indicating that the fonts https://my.idps.address.com/assets/base/fonts/fa-solid-900.ttf and https://my.idps.address.com/assets/base/fonts/fa-solid-900.woff2 could not be found.
The requested assets can be found on the server at for example https://my.idps.address.com/simplesaml/assets/base/fonts/fa-solid-900.ttf

Doing a bit of digging, I think the issue was introduced in the SimpleSAMLphp asset repository in this commit