The wizard says I'm missing a file

That message means the wizard is looking for something an earlier step creates.

You haven't run that earlier step yet. Run the wizard that comes first, then come back. The message usually names which one.

The file was renamed or moved. The wizards look for exact file names in your folder. Rename it back, or run the earlier wizard again to recreate it.

Tip: leave the files where the wizards save them. If you want a copy somewhere else, copy it and keep the original in place.