Upgrades are free for up to six months after the purchase of a license. But you're not stuck.
Reinstall your purchased version and, if necessary, re-register with your code. It will continue to work as always. The installer is normally saved to this PC path...
"C:\Program Files (x86)\NCH Software\VideoPad" (or a similar path without the (x86).
If you cannot find it there, download it from here. Ignore virus prompts. ANY VP version can be test driven without a license, but features will be limited.