The only two options I know would be to go back to an old version of the document (often Word lets you do this even if you didn't save different copies) with active citations (you could use Word's merge function so as to not lose more recently written text) or to manually relink, I'm afraid.

@ajangir_27: The complete answer is provided by adamsmith above.

sir ..may you explain me that what the use of this unlink option in zotero...if i do not do my document with citation unlink...what the problems may i face?

thanks

Why on earth would you put a function such as Unlink, which is a. capable of causing serious difficulty if used inadvertently b. irreversible on the main Zotero menu in Word.
And if you must put it where it can easily be accidentally clicked, surely you should add an "Are you sure?" dialog box before the action takes effect.

and it's not actually irreversible when inadvertently clicked.
Standard undo restores the field codes as does just not saving the changes in the Word doc.

It's only irreversible once you've saved the document over the version that contains field codes and then closed the word processor.

If you did this in spite of the warning displayed by Zotero and then saved your document over your last version and then closed your document you're indeed screwed

..and yes it is my fault, but creating documents to check word counts for publication is important and I think Zotero should look at this issue.

Zotero pops up a message when you try to unlink citations: "Removing field codes will prevent Zotero from updating citations and bibliographies from in this document..." and gives you the option to Continue or Cancel

The word count issue is a Word bug that is fixed in current versions of Word and, as far as I know, has never affected the Word Count button, just the count automatically displayed at the bottom of the Window.

And that includes using the Word Count button in the Review tab?
Then they simply never fixed this in Word for Mac. Both counts are correct in Word for Windows. I don't really see what Zotero can do about that, I'm afraid. Zotero uses a standard Word feature for its citations.

It has never worked on a Mac, hence the saving file to different names unlinking and checking count, lack of sleep, and deadlines and I resaved in a split second...screwed, I hope no one else does this!