When one gets a Keynote template in a .kth file (the Keynote extension for templates), the correct way to install it is to:
- Open the .kth file with Keynote
- In the File menu, click on Save Theme...
- The file will be stored in /Library/Application Support/iWork/Keynote/Themes.
This also works with .key files (the Keynote extensions for presentation source).
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