Starting in version 10.7, the generator throws an error message if a derived word is being created from a word that doesn’t exist in the language. For example, if the user writes the formula God of War : n = war god but the language has no word for war. This may happen because: 1) war was never added in the first place, 2) war was misspelled, or 3) war is itself a derived word created from another root word and added to the Derived Words field after God of War.
Due to a bug in previous versions, the generator sometimes created instances of scenario 3. It just never used to warn you! The important thing to know that nothing about your language has really changed, as those derived words were never created in the first place. Resaving the settings file will remove the faulty derived words. But it’s worth knowing that your language doesn’t have those words!