I tried updating to SDK 1.6.477 and also to EyeXEngine 2.0.2.219 but neither helped.
Apparently the problem lies in the heart of txGetState(hContext, TX_STATEPATH_EYETRACKING, &hStateBag); It’s returning a null hStateBag.
I will try switching to the asynchronous version txGetAsyncDataContent as shown in the MinimalStatusNotifications.c in the SDK 1.6.477