Save Project File AS routinely, giving it a unique # or name, so as not to overwrite prior saves. Using Save Project Files (no AS) will overwrite. Then you can restore a project to the state it was in when saved. Just double-click the VPJ file (which isn't playable).
Close Videopad, then restart it. Use 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.
Before you reload the project, under OPTIONS | DISK tab Clear Unused Cache Files. It's a good idea to do this each time a new project is begun.
Track 1 - the background video
Track 2 - the scaled and positioned insert video
Is this how you have laid it out?
If so, and it still doesn't work, upload and share the project. It's easy, quick and can be private. Just follow these steps and someone will check out the issue...
1. With your project on the timeline, click on MENU at the top-left. Click FILE|BACK UP PROJECT FILES TO FOLDER. Choose a folder and SELECT FOLDER.
2. Locate the saved, numbered folder - not the export file or only the VPJ. Upload it to a free server - Google Drive, MS OneDrive, etc.*
3. Get a shared, public link. If using Google Drive click GET SHAREABLE LINK. Click the blue "Change to anyone with the link..." Then click COPY LINK | DONE.
4. Paste that link here, or click the folder, above top-right in this forum, and message it to me. This is private and won't be shared.
* Before uploading, right-click the folder, click PROPERTIES. Look at the File Size to confirm that it's not too big for the free space on the server.