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Important: Workbook links are considered potentially unsafe and must be enabled when you open a formula workbook.When you open a formula workbook, click Enable Content in the Message Bar to allow the workbook links to function. If you don't, Excel keeps the most recent values and disables refreshing the links with values from the data workbook.

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解决激活错误. 如果 Microsoft 365 无法激活，其最后会变为未授权，且 Microsoft 365 的所有编辑功能都会被禁用。 Microsoft 可能由于多种原因变为未授权。

Important: You don't need to remove old security information unless there is an account security risk (e.g. someone else has access to your old mailbox).

Get Microsoft billing support. Find help with Microsoft Store purchases, subscriptions, refunds, payment options, and checking your order history.

Important: When you break a link to the source workbook of an workbook link, all formulas that use the value in the source workbook are converted to their current values.

Learn how to tell if your Office software is genuine. To help determine if your Microsoft software is genuine, go to our How to Tell site for more information. Here you'll learn about authentic packaging, including what to look for with product key labels, and Certificate of Authenticity (COA), how to report counterfeit software, and find out what your shopping and licensing options are.

There are some common two-step verification problems that seem to happen more frequently than any of us would like. We've put together this article to describe fixes for the most common problems.