Contact Form 7 cause HTTP 500 error

You need change in .htaccess file and in local setup folder name set as "wordpress" but in live site we have to change this name.

Before

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /agilitycards/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /agilitycards/index.php [L]
</IfModule>

# END WordPress

You need to replace with below code in .htaccess file.

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress