I have unsuccessfully tried whole day today to get the api working with my project using c# and vb2015 . Your sample console application does not work. I was wondering if you have tested the sample projects cs_sample_stream.csproj in tobii_interaction_lib_windows_x64_0.7.340_beta folder with vs 2015. It does not work for me. Sadly i have given up on this. I have got tobii Eye Tracker 4C bought from Amazon. Unfortunately unless we know this tracker meets our requirements we cannot commit ourselves to purchasing development license. As I said this is a proof of concept project.