Also for line 93.

Seen in journal logs for Plasmashell on Plasma 6 Wayland git master.

Relevant code in InfiniteList.qml does this:

        switch(infiniteList.viewType) {
            case InfiniteList.ViewType.DayView:
                infiniteList.itemAtIndex(0).gridModel = previousAlternativeBackend.item.daysModel;
                infiniteList.itemAtIndex(2).gridModel = nextAlternativeBackend.item.daysModel;
                break;

            case InfiniteList.ViewType.DecadeView:
                infiniteList.itemAtIndex(0).gridModel = previousYearModel.item;
                infiniteList.itemAtIndex(2).gridModel = nextYearModel.item;
                break;
        }

My guess is that itemAtIndex(0) is null at the moment it's called.