A mistake has recently been introduced when changing IS.php and moved line saying 'epcoordinator' => [ 'noratelimit' => true ], // T131684 into the arbcom group definition.
This code cannot work. See codeblock below.
8377 '+cswiki' => [ 8378 'autopatrolled' => [ 'autopatrol' => true, ], 8379 'bot' => [ 'ipblock-exempt' => true, ], // T44720 8380 'arbcom' => [ // T63418 8381 'browsearchive' => true, 8382 'deletedhistory' => true, 8383 'deletedtext' => true, 8384 'abusefilter-log-detail' => true, 8385 'abusefilter-view-private' => true, // T174357 8386 'abusefilter-log-private' => true, // T174357 8387 'epcoordinator' => [ 'noratelimit' => true ], // T131684 // This should be after 8388 8388 ], 8389 'rollbacker' => [ 'rollback' => true, ], // T126931 8390 'patroller' => [ // T126931 8391 'patrol' => true, 8392 'patrolmarks' => true, 8393 'unwatchedpages' => true, 8394 ], 8395 ],