Image Upload Error

Hi,

Regarding RT V4.4

When a user wants to upload a image via the ‘Media Manager’ at the bottom of the listing, it gives this error : SyntaxError: JSON.parse: unexpected character

And when they try to upload it at the ‘Display Image’ uploader it gives this : Fatal error: Cannot redeclare get_file_description() (previously declared in /home2/l2travel/public_html/wp-admin/includes/file.php:58) in /home2/l2travel/public_html/wp-admin/includes/file.php on line 71

I have tried it myself too thinking that maybe the image name or something might not be accepted, but it still gives the same.

Does anyone know what might cause this?

Thanks
Roelf