The data file shows a file with 1688KB of data.
That suggests an empty database.
I am attaching a screen capture of what happens when I now try to open the database.
The error message says the database is already in use. If the same error is happening, use
Task Manager to see if there is already a
viddb.exe or some other process running that may be accessing the database.
If the program is unable to find or use the last used database, it will create another at the default location—which is what the error message is referring to. It obviously shouldn't overwrite an existing database of the same name. Are you sure your original database does not have a different name or exist in some other location? Try the installation folder. If not there, search the computer for '*.pvd'.
I'm guessing PVD may not have shut down properly. When you started it again, it was unable to open the last used database because it was locked by the first instance. So it opened a new, empty database. Hopefully, the original database still exists somewhere.