Sorry to hi-jack but I am having the same exact issue. After upgrading to V2.11 Tobii EyeX has stopped working after Windows Restart. “No eyetracker connected”. Nothing has changed except for installing the new Core installation.
The only way for me to use it, is to uninstall and reinstall every time I want to use my Tobii Eye.
Using Tobii.EyeX_2.1.1.293 also works. Something is obviously wrong with the new V2.11
It would be great if I can at least find out the latest working version before V2.11 as my only option is V2.1.1 as this is working flawlessly.