Microsoft is preparing a significant change that will affect users of Office 2019 for Mac, despite the software being sold as a one-time purchase. Beginning July 13, Microsoft will no longer renew the security certificate used to validate Office 2019 licenses on macOS, causing affected applications to enter what the company calls “reduced functionality mode.”

Once this happens, users will still be able to open and view existing files, but they will lose the ability to edit, save, or create new documents in applications such as Word, Excel, PowerPoint, Outlook, and OneNote. For many customers who purchased the software under a perpetual license model, the change may come as an unwelcome surprise.

The decision has also drawn attention because it appears to contradict statements Microsoft made when support for Office 2019 officially ended in October 2023. At the time, the company stated that the applications would continue to function after support ended. However, Microsoft quietly revised that guidance last month, removing references suggesting the software would remain fully operational. The updated wording instead reassures users that their data will remain accessible, without explicitly mentioning the upcoming loss of editing capabilities.

Office 2021 for Mac will face a similar certificate issue on the same date, but users of that version are expected to receive a certificate update because the product remains within its support lifecycle. Support for Office 2021 is scheduled to continue until October 13, 2026.

According to Microsoft, Office 2019 users will not be able to resolve the issue through reinstallation or software updates. Because the product is no longer supported, it cannot receive the certificate update required to maintain full functionality.

Older versions of Microsoft 365 for Mac and iOS may also encounter certificate-related problems, although those versions can generally be fixed by installing the latest updates. Users who want to continue editing documents without interruption will need to upgrade to Office 2024 or subscribe to Microsoft 365, both of which remain fully supported by Microsoft.

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