C# does not allow structs to have initializers, the reason why has been debated before, see here: ( Why can't I initialize my fields in my structs?Why can't I initialize my fields in my structs? )
Simply remove the = false part from your field declarations.
Note that Boolean fields are false by default, making your assignment completely unnecessary.
If you absolutely need fields to have initialized to non-default values then you can still define an additional constructor that sets those values, however it cannot be the default (parameterless) constructor. One alternative option then, is to use a static factory method.