Cannot read property \'userID\' of null

TypeError: Cannot read property \'userID\' of null

at Ui.getcommonWords (<anonymous>:4210:948)

at Ui.observer (<anonymous>:4210:178)

at Function.i.safeCallback (<anonymous>:2:2495001)

at c.<anonymous> (<anonymous>:2:2536955)

at l.doUpdates (<anonymous>:2:2555279)

at Vn (<anonymous>:2:2631258)

at er (<anonymous>:2:2634428)

at Kn (<anonymous>:2:2633845)

at Kn (<anonymous>:2:2633964)

at Kn (<anonymous>:2:2633964)