What i have done.. (Theme dokuwiki)
i changed the logo.png in /app/data/ > templates > dokuwiki > images

Now it works!
But if i change the Theme to mikio and back to dokuwiki than the dokuwiki logo is restored!
In mikio i found no way to change the logo.

Also if i stop and start the dokuwiki app the original logo is restored.

If i look in the html there is <img src="/lib/tpl/dokuwiki/images/logo.png" width="64" height="64" alt=""> (theme dokuwiki)

Any idea how to fix it?

thanks in advance