Warning: Illegal string offset ‘saved’

I used your plugin and see the problem here https://chtarchitects.com.au/projects-3/aged-care-retirement-living/baptcare-wyndham-lodge-werribee/

Warning: Illegal string offset ‘saved’ in /var/www/vhosts/charchitects.com.au/httpdocs/wp-content/plugins/nextgen-gallery/products/photocrati_nextgen/modules/nextgen_data/package.module.nextgen_data.php on line 2607

How can I solved this? Please help me as soon as possible.
Thank you