404 Page for Multi-lingual Page For my multi-lingual-Page (de + en) I've made a 404.html-File in my templates-Folder with a language-changer for html-content-output like
{% if craft.app.language == 'de-CH' %}&lt;p&gt;Hallo&lt;/p&gt; {% else %} &lt;p&gt;Hello&lt;/p&gt; {% endif %} 

When I open the 404-pages local (localhost/404 and localhost/en/404) it works. Also when I open them in live with direct url (www.example.ch/404 and www.example.ch/en/404) everything works fine.
But when I will open a wrong URL like &quot;www.example.ch/tesxt&quot; (correct URL: www.example.ch/test) I get a HTTP 404 – Not Found – yii\web\NotFoundHttpException Template not found: tesxt
Settings:

I only have one index.php
I only have one 404.html
in general.php: 'devMode' =&gt; false,
the 404.html is directly in templates-Folder (src&gt;templates&gt;404.html)
installed Plugins: DigitalOcean Spaces Volume, Freeform, Redactor (I think these will not disturb the 404 page)
Craft Version: 3.5.17
PHP-Version: 7.3.17
I don't know exactly why. But I did the Redactor updates in Craft, uploaded the new vendor folder to the hosting provider and now it works.