TL;DR If Microsoft Copilot is not working in Excel, compare the same account in Excel for the web and desktop Excel before changing anything destructive. Common causes include the wrong signed-in account, stale browser or Office sessions, workbook restrictions, unsupported file context, tenant policy, add-ins, or network filtering. Record the account, platform, workbook location, and … Continue reading Microsoft Copilot Not Working in Excel: Fix Missing, Greyed-Out, or Failing Copilot