“You don’t have permission to access /wp-comments-post.php on this server. “

I used to have problem with posting certain links. After reading this, I could resolve the problem by uploading a .htaccess-file with the following content into my wp-admin folder: “SecFilterScanPOST Off”
Unfortunately, I still can’t post certain links in the comment section. I get the following error:

“You don’t have permission to access /wp-comments-post.php on this server.”

Can I somehow alter the .htaccess-file so neither posts nor comments are scanned?

Thank you for your help in advance!