By the way, I am using Word-2007. Is this related to the old version? The interesting thing is that it adds quotations without any problems up to a certain point in the work. But after a point, even if I press the button, I can't get a response. After a while after pressing the button, the cursor starts blinking. The quote screen does not appear. The button remains dysfunctional.I tried uninstalling and reinstalling Zotero. I should also say that my thesis consists of approximately 1500 pages and contains hundreds of references. Maybe that's why Zotero isn't working.

Please have a little patience—it’s not necessary to bump a thread every two hours. Zotero developers and volunteers read every thread.

If your document is very long, the word processor plugin can slow down, especially in Word for Mac. If possible, try to use a Windows machine to finish your document. You can also try the following steps to speed up the document as you write:

1. Turn off automatic updates in Document Preferences in the Zotero tab
2. Delete the bibliography from your document

When you have finished writing, re-insert the bibliography to update your document and citations one time. This might take a while but let it run.

I'm sorry if it bothered you. Thank you for your answer. I am already using Windows. I tried your suggestions. I deleted the bibliography. I turned off updates. Unfortunately, there was no progress. Pressing the "Add Cite" button after the final part of the work does not work. I will install Word 2010 version. Let's see if the problem persists.

Zotero works quite well with the _free_ LibreOffice writer program. You can import your MS Word documents but will almost certainly need to re-do your Zotero citations.

You can move a Word document with Zotero citations to LibreOffice, but you need a working Zotero plugin in Word to do that.

https://www.zotero.org/support/kb/moving_documents_between_word_processors