Hi @nurderfsv, sorry to hear about your difficulties. Have you tried ensuring via Nuget that the Tobii Interaction Libraries are installed? This needs to be done for each new project for the Core SDK DLL’s to be correctly loaded.
It may also be helpful for you to check out the ready to run sample applications for the Core SDK which you can download @ https://github.com/Tobii/CoreSDK
Please let us know how you get on and if we can be of any further assistance.