Hello,
I got this from NextGen Gallery support this is the next thing that I am gonna try.
define( 'WP_DEBUG', true );
(This turns on debug mode, you can set this to false to stop from generating the output on your site)
define( 'WP_DEBUG_DISPLAY', true );
(This makes the errors visible, if you set this to false the messages will go away but your site will still be in debug mode, as long as your galleries work as usual, it is OK to deactivate this)
define( 'WP_DEBUG_LOG', true );
(This creates a file where error output is stored regardless of debug display being enabled or not, normally it is a file called debug.log inside your wp-content folder)
