[For 1.8] MyBB-PageManager

[frostschutz]

This user has been denied support.

groups is a reserved keyword since mysql 8.0.2 - you'll have to quote it

$query = $db->simple_select('pages','pid,name,url,groups,deviceselect,online','enabled=1');

if quoting does not work you can also put * instead of pid,name,url, groups, ...

or maybe your mybb_pages table has no groups entry at all but it should've been added by the plugin's update code (which runs when you deactivate/activate)