Start by opening the dotm/dot template in Word. Go to Debug->Compile Project to ensure there are no code errors.Go to View->Macros->View Macros (Ribbonized Word) or Tools->Macros->View Macros (Word 2016) and click 'Edit' for one of the Zotero macros.Open the template from inside Microsoft Word.Word 2016 (for the ribbonized dotm template).Otherwise older versions of Word may fail to function properly. Templates should be built with the oldest version of Word to be supported.
This is a Firefox add-on that consists of a library written in ObjC that communicates with Microsoft Word out of process using AppleScript, a js-ctypes wrapper for said library, and a template that is installed into Microsoft Word to communicate with Zotero.