me too!!! I've got Virb Edit 5.4.3 Garmin wrote in version 5.4.3 has been fixed startup issue on MacOS Mojave.. perhaps they tested on a Windows machine or in a high sierra osx :-)
In my case, I update the application version, but the OS still using the version before.:o So... my soggestion is: delete current Virb Edit and Install it again with the last version.