I had a problem with my old website some time ago and wrote a blog post about it. Now I have transferred this post to my new blog. It’s about the following error message:

The problem
I tried to load a resource from the origin of a domain, even though I’m currently in a subdomain. I’ve tried to access https://konzeptcode.com from https://ht.konzeptcode.com . This must be allowed separately.
The solution
You have different ways around this problem. If you only temporarily load the resources from there and use Google Chrome, I recommend you to install a plugin.
However, if you are always going to load resources from another subdomain, you can bypass this error message by making a change to the htaccess file.
Header set Access-Control-Allow-Origin "*"
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
Header set Access-Control-Allow-Origin "*"
RewriteCond %{HTTP_HOST} ^konzeptcode.com$ [NC]
RewriteRule (.*) https://www.konzeptcode.com/$1 [R=301,L]
# add a trailing slash to /wp-admin
RewriteRule ^wp-admin$ wp-admin/ [R=301,L]
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^(wp-(content|admin|includes).*) $1 [L]
RewriteRule ^(.*\.php)$ $1 [L]
RewriteRule . index.php [L]