PDF-XChange Co Ltd :: Knowledge Base :: Why can't I see PDF previews in MS Outlook?

KB251
May 02, 2025 09:14 AM

Why can't I see PDF previews in MS Outlook?

Question:

Why can't I see PDF previews in MS Outlook?

Note: This article is being written at a time when Microsoft has recently converted Outlook to a “web based” application, which has complicated access to the preview handler as well as toolbar add-ins. If you are experiencing any issues of this like with the “(New) Outlook” application, please email support@pdf-xchange.com with an explanation of the issue, and we will do our best to assist you.

Answer:

As with any tool that interacts with Third-Party applications, do ensure that both the Editor, and your MS Office installation are fully up to date. If you are using a “Preview” version of MS Office, please roll back to the current release, as we cannot easily debug the issue in a volatile release version.

If you can reproduce the issue in the latest release of MS Office, the simplest resolution to these issues is often to re-register our Shell Extensions, detailed instructions are available here. Note that in most cases, a system restart will be required for the changed to be made.

If re-registering the shell extensions fails to restore the preview, others have found success in using the Editor for this process.

Please first ensure that all instances of Outlook are closed (Check your system tray and “right click > exit” if the Outlook icon is present).
Once Outlook is closed, Open the PDF-XChange Editor.
Push “Ctrl+K” to open the Preferences menu (Alternatively, you can click “file > Preferences” in the Ribbon UI, or “Edit > Preferences” in the Classic UI)
From the Preferences menu, open the “File associations” category, and set “Preview Handler for PDF files” to “Yes”, then click Apply, and then OK. (Note: When you click apply, the “yes” will revert to “Do not change” this is intended, and is not an error or indication anything failed to change).
Close the Editor, and re-open MS outlook. Previews should now work as expected.

Previous Versions

(Note that that latest releases of our software are only officially compatible with Microsoft products that are still supported by Microsoft, including those under “extended/long term” support. Office 2010 is no longer supported by Microsoft as of October 2020 and so we cannot guarantee our products will remain backwards compatible.)
This section remains in place for user with older versions of both our PDF-XChange products, and MS Office.

A 64 bit version of PDF-XChange Viewer/PDF-XChange Editor is being used in conjunction with a version of MS Outlook older than Office 2010.

MS Outlook versions prior to Office 2010 are available only in 32 bit - even when they are used on 64 bit PCs. This results in compatibility issues when 64 bit version of our products are used, in particular with the Shell Extensions provided for preview/search options. We have taken significant measures to resolve this issue - please see below.

Resolution:

The following steps re-register the DLLs and rectify the problem in most cases:

Uninstall all PDF-XChange applications.
Restart your computer.
Download and reinstall the latest versions of the products, which are available here.

If the steps above do not resolve the issue then please contact us and with the following information: