A new version of Tobii EyeX for Windows is now available on the update server and for manual download. It is based on the EyeX for Windows 0.8.14 and only contains bug fixes to prevent the EyeX Engine to crash for some users. There are no changes in the API since 0.8.14, so you can still use the EyeX SDK 0.21 and run applications based on 0.8.14.
If you want to do the upgrade manually, you can download the new release here on the Tobii Developer Zone. Note that you might need to uninstall all your previous Tobii programs to succeed with the update.