I received this response from support:

Dear Deborah,



Thank you for contacting Reallusion.



If you want to reset the preference default setting, the current method is to reset all settings.



If you accept to overwrite all settings in CTA5, we provide a reset tool, please execute the attachment file and it will directly reset all the settings.

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The only way to restore the preferences to their defaults in Cartoon Animator 5 is to contact support and get access to the reset tool. I would like a button in the preferences menu to restore the settings to their defaults. This feature is available in most modern software applications.