A bug in the classic version of Outlook prevents encrypted emails from being opened. Microsoft is working on a solution.
Those still using the old version of the Outlook app may have been unable to open encrypted emails for several days. The update to version 19426.20218 causes an error message when opening an encrypted email. When opening the email, you see an attachment message_v2.rpmsg, but it is not possible to read the email.
Microsoft confirmed on January 6 that it was ‘investigating’ the bug, but a fix has not yet been released. In the meantime, Microsoft is sharing two temporary workarounds. Either you can adjust the encryption settings, or you can revert Outlook to an earlier version that is not affected by the bug.
Old to new
Microsoft has been pushing the new Outlook app for over a year. Coincidence or not, the classic version seems to be increasingly plagued by bugs that disable certain functionalities. A malfunction in November broke the connection between Exchange Online and Outlook, and a month earlier the classic mail app itself was completely unreachable on Windows.
The classic Outlook app will still be supported by Microsoft until 2029, but you have to look hard to find it. In this guide, we show you how to use the classic Outlook in 2026.
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