I launched my MS Outlook 2019 client a few hours ago and if I try to preview or read any message the text in the body is blank. Luckily everything looks fine if I log into the webmail applications of my ISP or at Outlook.com from my browser.
There have been a flood of posts about this in the MS Answers forum in the past few hours – see today’s As of a short while ago (10:00AM 2021-05-11), my Office 365 Outlook has stopped correctly rendering HTML email for one example. My May 2021 Patch Tuesday updates haven't been installed (I've deferred them to a later date) so I suspect this is yet another widespread problem with the backend Outlook.com servers.
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Dell Inspiron 5584 * 64-bit Win 10 Pro v20H2 build 19042.928 * Firefox 88.0.1 * Microsoft Defender v4.18.2104.10 * MS Office Home and Business 2019 C2R v2104 Build 13929.20296
Microsoft identified the root cause of the issue affecting viewing email content in Outlook and released a fix last night. If you launch and close MS Outlook a few times emails should be displayed correctly again. Lawrence Abrams' 11-May-2021 Microsoft Outlook Bug Prevents Viewing or Creating Email Worldwide in BleepingComputer includes the text of Microsoft's incident status message EX255650, which states in part:
Title: Issue affecting viewing email content in Outlook
User Impact: Users may be unable to view email message content within Outlook.
More info: Impact is specific to the Outlook client and users with access to other protocols, such as Outlook on the web or the Outlook mobile app, can view message content in those platforms as a potential workaround while our fix is applied.
Current status: We’ve identified the underlying cause of impact and are applying a fix. This fix will reach all affected users incrementally over the course of the next four-to-five hours. Once users receive the fix, they will need to restart their email client to apply the fix. In some circumstances, users may need to restart their client a second time for the changes to take effect. We expect to complete this process and restore service for all affected users by May 12, 2021, at 3:00 AM UTC. ...
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Dell Inspiron 5584 * 64-bit Win 10 Pro v20H2 build 19042.928 * Firefox 88.0.1 * Microsoft Defender v4.18.2104.10 * MS Office Home and Business 2019 C2R v2104 Build 13929.20372