error: 406 not acceptable

[bigfish5]

hello,
i'm getting the 406 error when trying to perform a function on my ecommerce site

Not Acceptable
An appropriate representation of the requested resource /mockup/wp-admin/post.php could not be found on this server

i already tried adding SecFilterEngine Off, SecFilterScanPOST Off, and SecRuleEngine Off to my htaccess file but i'm still getting the same error

admin, please unblock my page, thanks