Please provide more information. It appears that you are using a numbered style -- is that correct? Are you asking about missing items in your bibliography? Are the references in your bibliography not matching the numbers in-text? If you describe in detail the problem and give examples someone can guide you to track down the flaw in your document that led to your problem.

It sounds like some of the Zotero field codes in your word processor document may have been damaged and aren't being transferred properly to your bibliography. What word processor are you using? Have you shared your document with anyone who might have opened it using a different word processor and then saved it in another file format?