I was testing the latest TypeScript in VS (644ea82) and I had some error popups when typing.
It only happened on invalid code (because I was typing) so I'm not sure if this really is an issue but see the attached image

Feel free to close if this is just expected because I'm running in DevMode.

edit oops, I forgot to add the code...

class foo {
    public bar() {
        this
    }
}

It happens when typing a . (dot) right after this but also when trying to type a comment there.