Thanks for sending the file, Todd. I can now reproduce the problem: if you go into the Paragraph Styles dialog and click the “save as default” button for a style you’ve not edited during that session of the dialog, it fails, due to a small logical error in the dialog code, which we’ll fix. In the meantime, you should find that if you make some changes to the style in the dialog session, you can successfully save it as a default. Sorry for the inconvenience caused.