Panel showing blank page after changing htaccess

Hi,

I added a rewrite rule in my .htaccess:

RewriteCond %{HTTP_HOST} !^www.example.tld$
RewriteRule ^(.*)$ https://www.example.tld/$1 [R=301,L]

Now I can’t access the panel. The page (example.tld/panel) would load, but doesn’t display a login or anything else, it’s just a blank page. I have removed the two lines and restored the old .htaccess, but the panel remains inaccessible.

While searching through the forums, I’ve found a possible solution (No panel login with www), but I’m unsure which config file it’s referring to.

Thanks for your help!

/site/config/config.php, but the syntax has changed since then, see url | Kirby CMS