iBooks Author: If you see document warnings
You might see the Document Warnings window when you:
Address document warnings
Do any of the following:
View the Document Warnings window: Choose View > Show Document Warnings.
Replace a missing font: Select the missing font and choose a font from the Replace Font pop-up menu.
Prevent the window from appearing automatically: Deselect “Open this window when problems occur.”
Clear all warnings: Click Clear All.
You can copy warning messages and paste them into a document for reference later; these messages could be useful for diagnosing problems.