I tried the plugin troubleshooting and realised the issue occurred only in one section. After I deleted the whole paragraph, the issue went away. Everthing is going fine with new citation added to other sections in this doc. Other solutions like creating a new doc, copying and pasting to a new doc, saving a copy to local hard drive, and renaming to remove space did not work. I opened previous backups to check and found all backups created since April 2023 had this issue in the same section of that doc. The backup created in March 2023 did not have such an issue. Is this a significant problem? Caused by zotero or Office Word? Thanks