I got it working by switching from x84 dll to x64 dll. I have another related question.
The file Tobii.StreamEngine.Interop.cs in stream_engine_windows_x64_4.1.0.3.zip doesn’t compile.
1>C:\Users\tqphan\source\repos\GazeServer\GazeServer\Tobii.StreamEngine.Interop.cs(475,102,475,137): error CS0246: The type or namespace name ‘tobii_calibration_stimulus_points_t’ could not be found (are you missing a using directive or an assembly reference?)
I have to comment out line 475.
Possible fix?