The 'free' version is a trial. You are not required to update/pay, but there will be limitations, such as export formats. Try AVI - it usually succeeds.
If it was licensed before, reinstall your earlier version and re-register if necessary. Use it fully as long as you like.
Updates (no obligation) are free for six-months after registering. And you can always test drive the latest, unlicensed, to see if new features appeal to you.