Unfortunately the Word Plugin [with Zotero 7.0.1] does NOT work either on new or old word documents [I use MS Office Word 2010]. In both cases a message appears in Word that "Zotero is not opened." For now I have gone back to Zotero 6.0.36 version and everything is working fine again. I'll wait until an easier fix can be provided: Thank you!
You'll need to say what the actual problem is that you're experiencing and provide a Report ID after reproducing it.