What's the format of the file? What version of Videopad is being used? Is it out of sync on the timeline or after export? If the latter, what are the settings?
Try the latest version. For licensed users upgrades are free for up to six months from purchase date. After that, VP will continue to fully function but a fee will be required in order to register the newest. Retain your old install file and registration info.
Share the file and someone here will take a look. Upload it to a free server, such as Google Drive or MS OneDrive, get a shareable (public) link, copy the link and paste it here or to me in a Private Message via the mail envelope at the top-right of this forum.