If you’re running an older system…
Roger Bolton from CoreMelt warns you to update your CoreMelt plug-ins to the latest version if you are running the latest macOS, High Sierra OSX 10.13.
Roger explains, “Only versions released after 9/10/17 will function correctly in High Sierra. In Earlier versions, you may experience crashes when applying a small number of the effects. To apply this update you do not need to uninstall your plugins, please download and install them again.”
He also mentions that if you did a clean install when you updated your OS you’ll need to re-enter serial numbers. If you’re planning to upgrade your OS with a clean install, make sure you save them someplace safe.
His advice is to hold off on upgrading if you’re in the middle of a project, but this is common sense. Never upgrade during a project unless you absolutely have no other choice.