Outlook in Edge - Preview of attachments will not open when selected, instead downloads immediately

Question

When I open an email in Outlook in the browser (already tried different browsers) and want to preview the attached file by clicking on it, the following things happen:

• PDF: I can select 'Preview' or 'download'. When selecting 'preview', a preview screen opens, but doesn't actually show the file-preview. Instead it shows the 'thinking wheel', never actually loading anything in. The file does get downloaded. (See the attached 'Image 1')
• MS Word-document: I can only select 'download'. No preview screen opens. The Word document downloads immediately, no preview is shown (see the attached 'Image 2').

A few months ago I did not have this issue; when clicking an attached file, it would always show a preview.

Is it possible to change the settings and show the previews automatically again? If so, how?

Best regards,

Maarten

Answer 1

@Maarten van Wel

> A few months ago I did not have this issue; when clicking an attached file, it would always show a preview.

Did you install install or upgrade to Microsoft Exchange Server 2019 Cumulative Update (CU) 8 or Microsoft Exchange Server 2016 CU19?
If yes, please refer to "PDF preview function in OWA leads to download action unexpectedly", there was a changed feature which was introduced by Microsoft Exchange Server 2019 CU7 and Microsoft Exchange Server 2016 CU18, such this issue is a side effect of blocking inline images from opening in a new tab.

To fix this issue, install one of the following updates:

• For Exchange Server 2019, install the Cumulative Update 9 for Exchange Server 2019 or a later cumulative update for Exchange Server 2019.
• For Exchange Server 2016, install the Cumulative Update 20 for Exchange Server 2016 or a later cumulative update for Exchange Server 2016.

---

If an Answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.