After a while, I am unable to share to Screencast.com from Snagit. Clicking the Screencast button does nothing.
This problem has been addressed in Snagit 4.1.5 and later. Update by opening Snagit and browsing to the menu bar item Snagit > Check for updates.
This is a known issue that will be fixed in the next update for Snagit. Currently, the best workaround is to close out of Snagit and re-launch the application.