Hm. It works fine with txGetStateValueAsSize2 in the MinimalStatusNotification sample. So, it wouldn’t compile unless you used a TX_RECT?
Are you using txGetStateAsync or a state changed handler? If the former, what state path are you using for the txGetStateAsync call? It should work with both TX_STATEPATH_EYETRACKINGSCREENBOUNDS and TX_STATEPATH_EYETRACKING (though the latter includes many more states).