What version of Mojave is this? If you're not yet running 10.14.2, upgrade and see if that helps. Mojave requires you to grant Zotero permission to control Word, but that was very buggy in the initial versions of Mojave.

If upgrading doesn't help, go to System Preferences → Security & Privacy → Automation, see if Zotero appears with Microsoft Word under it, and, if so, make sure that Microsoft Word is checked.

Thank you for your answer.

However nothing is working properly.
I use Mojave 10.14.1 and I checked in security and Privacy that Zoero appeared under Word and Word was checked.

In Word n,o non-English latin character;
And after creating a new doc, I also failed when inserting a new zotero field with the same OSStatus error 1728.

This is the way my old Word text (March 2018) looks like:
Bodipy","journalAbbreviation":"Chem. Soc. Rev.","language":"en","author":[{"family":"Zhao","given":"Jianzhang"},{"family":"Xu","given":"Kejing"},{"family":"Yang","given":"Wenbo"},{"family":"Wang","given":"Zhijia"},{"family":"Zhong","given":"Fangfang"}],"issued":{"date-parts":[["2015",11,30]]}}}],"schema":"https://github.com/citation-style-language/schema/raw/master/csl-citation.json"}