Non-nullable field '_listBox' must contain a non-null value when exiting constructor. Consider declaring the field as nullable.

Non-nullable field '_items' must contain a non-null value when exiting constructor. Consider declaring the field as nullable.

Possible null reference return.

Dereference of a possibly null reference.

Possible null reference argument for parameter 'source' in 'IEnumerable<IItem> Enumerable.Cast<IItem>(IEnumerable source)'.

Possible null reference argument for parameter 'item' in 'void ShellView.SideMenuItemChanged(SideMenuItem item)'.

Because this call is not awaited, execution of the current method continues before the call is completed. Consider applying the 'await' operator to the result of the call.

Non-nullable property 'Path' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

Non-nullable property 'Default' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.