While restarting Windows, this message is displayed: "Snagit has prevented Windows from shutting down."
This issue falls in the Windows 10 Fall Creators Update.
Snagit 2018 and Later
This is a known issue that is fixed in Snagit 2018.0.1 and later. Select Help > Check for Updates in Snagit to install the latest version.
Snagit 13 and Earlier
As a workaround, turn off OneClick in the Snagit Recorder. This will allow Windows to shut down properly. To turn off OneClick, see this article.