Admiror Gallery cannot create thumbnails in /var/www/html/plugins/content/admirorgallery/admirorgallery/thumbs/RCOI29/.
Check folder permmisions!
Admiror Gallery: 5.0.0
Server OS:Apache/2.4.18 (Ubuntu)
Client OS:Unknown
PHP:7.0.33-32+ubuntu16.04.1+deb.sury.org+1