A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data
Dear Matt Mills,
It sounds like Office is still trying to authenticate against an old work/school account that was previously connected to Windows or Office. Since Excel opens and works after you dismiss the message, this is usually caused by a stale account reference.
Before creating a new Windows profile, since you've already uninstalled and reinstalled Office and even tried removing the recommended registry entries, I would suggest following the AI answer's recommendations first, as they cover the most common causes of this issue.
To help narrow this down, you could ask the customer:
- Does the issue occur only in Excel, or do Word, PowerPoint, and Outlook show the same prompt?
- Which version of Office are you using: Microsoft 365 Apps, Office 2024, Office 2021, etc.?
- Under Settings > Accounts > Access work or school, do you still see any old work account listed?
- Are you signed into OneDrive with a personal account, or is there any old work OneDrive still configured?
- If you create a temporary new Windows user profile and install/sign in to Office there, does the same message appear?
- Have you ever used any Excel add-ins connected to your former employer's Microsoft 365 environment?
If you have any questions or if I have misunderstood anything, please feel free to reach out. I'm looking forward to your update.