huangweiqiu → created an issue.
I got this issue just now by installing latest gin theme without toolbar module enabled what caused me couldn't access any admin page.
I had to use below code snippet to change the admin theme so that I can access the admin pages again.
$config = \Drupal::service('config.factory')->getEditable('system.theme');
$config->set('admin', 'YOUR_THEME')->save();
Even if I install toolbar,I still couldn't get the gin 4.0.2 working.
it seems that it also has conflicts with the module Ui Icons:~
2025/01/25 01:05:51 [error] 14876#17080: *377 FastCGI sent in stderr: "Uncaught PHP Exception Error: "Call to a member function getOption() on string" at H:\wemp\nginx\html\nkmz\modules\contrib\ui_icons\modules\ui_icons_menu\ui_icons_menu.module line 95" while reading response header from upstream, client: 127.0.0.1, server: localhost, request: "GET /admin/appearance HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "127.0.0.1:81", referrer: "http://127.0.0.1:81/admin/appearance"
huangweiqiu → created an issue.