new outlook Adobe can't open

Question

new outlook Adobe can't open

Telman Garakishiyev 5

Dear Microsoft Support,

We are experiencing an issue with New Outlook where users are unable to open PDF attachments directly from emails.

We have already tried the following troubleshooting steps:

Closed Outlook completely.
Checked the following directory: %userprofile%\AppData\Local\Microsoft\OLK
Confirmed that the Attachments folder already exists.
Renamed the existing Attachments folder to Attachments_old.
Restarted Outlook and tested the PDF attachment again.

However, the issue still persists.

Could you please investigate this issue and advise us on the recommended solution?

Thank you for your assistance.

Moderator note: tag (= Q&A categorization) modified to New Outlook for Windows

Chris Conlan 5 Reputation points

2026-10-02T13:50:24.23+00:00

We are experiencing the same issue with one end-user. I'm on the same version as this person and I'm not experiencing it.

We even tried a different PDF viewer and get the same error. If you open Classic Outlook it works fine.

The post where it says does it do the same thing in OWA, you can't compare it. In OWA you get preview, but you have to download the PDF to open it locally.
Sebastian Jasinski 5 Reputation points

2026-10-07T15:21:26.7233333+00:00

We have 2 users with same issue but it's not just Adobe. Haven't tested all Office apps but Word and Excel seem to do same.
Chris Conlan 5 Reputation points

2026-10-07T15:47:36.8466667+00:00

Glad I'm not the only one. We only have about 10 users using the New Outlook. It is only affecting one user right now.
Jonathan Petroons 0 Reputation points

2026-10-09T06:08:31.8733333+00:00

Hi everyone,

We are experiencing this problem with one user who is actively using Outlook New and the problem is also in her OWA. Tried on several device even in private navigation when it's her account the PDF Preview is crashing.

We can save the PDF file into One Drive and then open it but it's clearly not what the client want when she has a lot of PDF to look at.

The problem is not present in the Outlook Classic.

Best regards,

P.S: I think the tag isn't correct because the screenshot and explanation looks like the New Outlook
Stefan Blom 353.9K Reputation points MVP Volunteer Moderator

2026-10-09T14:23:17.9266667+00:00

I think the tag isn't correct because the screenshot and explanation looks like the New Outlook

Question moved to Outlook | Windows | New Outlook for Windows | For business. Thanks for pointing it out.

1 answer

Your answer

Chris Conlan 5 Reputation points

2026-10-02T13:50:24.23+00:00

We are experiencing the same issue with one end-user. I'm on the same version as this person and I'm not experiencing it.

We even tried a different PDF viewer and get the same error. If you open Classic Outlook it works fine.

The post where it says does it do the same thing in OWA, you can't compare it. In OWA you get preview, but you have to download the PDF to open it locally.
Sebastian Jasinski 5 Reputation points

2026-10-07T15:21:26.7233333+00:00

We have 2 users with same issue but it's not just Adobe. Haven't tested all Office apps but Word and Excel seem to do same.
Chris Conlan 5 Reputation points

2026-10-07T15:47:36.8466667+00:00

Glad I'm not the only one. We only have about 10 users using the New Outlook. It is only affecting one user right now.
Jonathan Petroons 0 Reputation points

2026-10-09T06:08:31.8733333+00:00

Hi everyone,

We are experiencing this problem with one user who is actively using Outlook New and the problem is also in her OWA. Tried on several device even in private navigation when it's her account the PDF Preview is crashing.

We can save the PDF file into One Drive and then open it but it's clearly not what the client want when she has a lot of PDF to look at.

The problem is not present in the Outlook Classic.

Best regards,

P.S: I think the tag isn't correct because the screenshot and explanation looks like the New Outlook
Stefan Blom 353.9K Reputation points MVP Volunteer Moderator

2026-10-09T14:23:17.9266667+00:00

I think the tag isn't correct because the screenshot and explanation looks like the New Outlook

Question moved to Outlook | Windows | New Outlook for Windows | For business. Thanks for pointing it out.

Answer 1

Helen Luu 3,385 Independent Advisor

Hello @Telman Garakishiyev

As you mentioned that you are using Adobe to open the PDF files, could you please help me with the following information so I can better understand the issue?

Have you tried opening the PDF file using Outlook on the web? If so, does the PDF open successfully there?
I noticed that your post is tagged with Classic Outlook. Have you also tested the same PDF file in New Outlook while using Adobe as the default PDF viewer?
Which version of Classic Outlook are you currently using?
When did the issue first start occurring?
If you download the PDF file locally, are you able to open it successfully using Adobe Reader or a web browser (such as Microsoft Edge)?

The answers to these questions will help determine whether the issue is related to Outlook, the PDF file itself, or the PDF viewer being used.

I look forward to your update.

Chris Conlan 5 Reputation points

2026-10-02T13:51:18.3233333+00:00

Downloading locally it works fine. The PDF viewer works fine, but when you press Open you get the error shown above.

If you open Classic Outlook you can open the PDF fine in your external PDF viewer/editor.
Helen Luu 3,385 Reputation points Independent Advisor

2026-10-04T12:37:55.1433333+00:00
Hi @Chris Conlan

Have you tried reinstalling the application?

Additionally, please try opening Outlook in Safe Mode:

Right-click the Start button and select Run.

Type Outlook.exe /safe and select OK.

I look forward to hearing from you.
Caitlin Hill 0 Reputation points

2026-10-07T15:49:40.2233333+00:00

I am having the same issue. I was able to double click on the attachment and it would open. Now it gives me the same error. I have done the following:

Closed Outlook and restarted.

Tried it on web outlook and attachment does open but not on actual APP.

I have clicked " repair" and "reset" in the app installation setting.

I have created an attachment folder

This started happening after Outlook was updated recently.

Please help- is this just an issue with the new outlook? nothing at all has changed on my end except that update. is there a way to uninstall the update and revert back to the OLD NEW outlook without using CLASSIC outlook?
Chris Conlan 5 Reputation points

2026-10-07T15:57:41.95+00:00

Double-clicking the attachment for the end-user didn't fix the issue. They were still met with the dialog box.

I'm unsure of a way to install an older version of New Outlook. Right now the end-user is manually downloading the PDF's because Outlook (classic) wasn't working properly for it (main reason we moved to the New Outlook).