In .htaccess file at site root directory edit following line:
<ifmodule mod_security.c>_x000D_
_x000D_
SecFilterEngine Off_x000D_
SecFilterScanPOST Off_x000D_
_x000D_
</ifmodule>_x000D_
_x000D_
<IfModule mod_rewrite.c>_x000D_
RewriteEngine On_x000D_
RewriteBase /_x000D_
RewriteCond %{REQUEST_FILENAME} !-f_x000D_
RewriteCond %{REQUEST_FILENAME} !-d_x000D_
RewriteRule . /index.php [L]_x000D_
</IfModule>
_x000D_
Just keep the mod_security rules like SecFilterEngine and parts apart from each other. Its works for apache server