Start Zotero and redirect the debug output logging to a text file.

zotero_log.cmd

:: Name    : zotero_log.cmd
:: Purpose : Start Zotero and redirect the debug output logging to a text file.
:: Details : CMD batch script for Windows, tested on Windows 10.

@ECHO OFF
SETLOCAL ENABLEEXTENSIONS
SET scriptdir=%~dp0
SET scriptname=%~n0
SET zoteropath=C:\Program Files (x86)\Zotero\zotero.exe

:: logfile's name: [scriptname]_YYYY-MM-DD_HH_MM_SS.txt
:: https://stackoverflow.com/a/19163883
FOR /f %%a IN ('powershell -Command "Get-Date -format yyyy-MM-dd_HH_mm_ss"') DO SET datetime=%%a
SET logfile=%scriptdir%\%scriptname%_%datetime%.txt

:: https://www.zotero.org/support/debug_output#logging_to_a_terminal_window
"%zoteropath%" -ZoteroDebugText > "%logfile%"

EXIT /B

https://forums.zotero.org/discussion/93967/zotero-debug-output-file-is-created-empty