I had the same problem with the Datalynx plugin. I've added the hidepicture field in the mdl_groups table.
ALTER TABLE `mdl_groups` ADD `hidepicture` INT(1) NOT NULL DEFAULT '0' AFTER `timemodified`;
It seems to work.
ALTER TABLE `mdl_groups` ADD `hidepicture` INT(1) NOT NULL DEFAULT '0' AFTER `timemodified`;
It seems to work.