PDF Preview Handler Not Working? Solved With 10 Proven Ways

Outlook gives users option to preview their PDF documents, but sometimes it gives an error regarding the PDF Preview Handler. This error is highly frustrating since it usually comes out of nowhere after you upgrade to later versions of Outlook.

The even worse thing with it is that there seems to be no solution to this problem other than using other PDF reader tools like Acrobat.

If you also face this issue, then you are in the right place. We have gathered some of the most effective and 100% working ways that you can try to fix PDF preview handler not working. Chances are that one or more of these solutions will resolve this problem at your end by treating its root cause. However, if you don't want to go through the tedious process of trying 10 different solutions one by one then you may download UPDF via the below button for conveniently viewing your PDFs.

Part 1. 10 Proven Ways to Fix PDF Preview Handler not Working in Outlook

Here are the 10 different methods you can try to resolve this issue with Outlook PDF Preview Handler on your PC.

Way 1. Make Sure the Office and Adobe Reader Have the Same Bit

When installing any software on your Windows PC, you must pick either 64- or 32-bit version, and it depends on your OS as well. In most cases, a 32-bit app will work on a 64-bit OS, but different-bit versions can cause compatibility issues among tools. So, if you face PDF preview handler not working issues, you must check both Office and Adobe Reader to make sure they have same bit.

Step 1: To check the details for Outlook, you need to run Outlook and click "File" then go to "Office Account" > for viewing "Product Information" and click "About Outlook". You will find the bit information here.

Step 2. To check the bit version of Adobe Reader, you need to open Adobe Reader on your computer, click "Menu" > "Help" > "About Adobe Reader". Now, you can find the bit information of your Adobe Reader.

Step 3: If both tools are installed in different bit versions, then you must download Adobe Reader in same bit as Outlook. Go to Adobe Reader download page and click "More Download Options" then select the right version to download.

Way 2. Enable PDF Preview Handler

Sometimes, disabling PDF preview handler in your tool settings can cause PDF preview handler not working. So, enable this setting in Outlook app to check if it starts working.

Step 1: Run Outlook then click "File" and choose "Options". Here pick "Trust Center" and go to "Trust Center Settings" for editing "Attachment handling" settings and uncheck "Turn off Attachment Preview" option.

Step 2: Click "Attachment and Document Previewers" then check "PDF View Handler" option before clicking OK.

Way 3. Disable and Enable the Internet

Chances are that connectivity problems might be causing the issue, so try disabling and enabling the internet connection.

Step 1: Go to Settings and click Network option. Now ensure that you don't have any ethernet connection with your PC and turn off Wi-Fi. Wait for a few seconds and turn the Wi-Fi back on or re-attach the ethernet cable. You may check network status to see if you are connected to the internet or not.

Way 4. Restart the Computer

Issues with RAM often cause problems with software where they stop responding like normal. Restarting your PC will clear RAM and solve this issue if that's the case.

Click "Windows" > "Power" > "Restart" and wait as your PC restarts. Try previewing PDF again in Outlook after PC starts.

Way 5. Disable Internet Auto-Detect

Internet Auto-Detect is a feature that might be causing issues with your PDF Preview Handler. You can resolve these issues by disabling this option.

Step 1: Open Adobe Acrobat Reader and click "Menu" > "Preferences" > "Internet" > "Internet Settings" > "Connections" > "Lan Settings"

Step 2: Uncheck "Automatically Detect Settings" then click "OK" > "Apply". Close all apps and restart PC.

Way 6. Run Adobe Acrobat Reader with Win 8 Compatibility Mode

Sometimes, running software compatibility mode with Windows 8 can solve the PDF preview handler issue, and that's what we will try here.

Step 1: Do right-click Adobe Reader icon and open properties. Now click "Compatibility" to check checkbox for running compatibility mode for, select "Windows 8", then click "Apply" > "OK".

Way 7. Set the Adobe Reader as Default PDF Handler

Downloading Adobe Reader and not setting it as default preview tool for PDFs can cause different issues including the one with PDF preview handler. So, you can try setting it as default tool to see if your Outlook starts working normally or not.

Step 1: Run Acrobat Reader then click "Menu" > "Preferences" > "General" and checkmark the option for enabling thumbnail previews in Windows Explorer. Click "Select As Default PDF Handler" to select Adobe Reader as default PDF Handler. Also checkmark the option "tell me if Adobe Acrobat is not my default PDF application" and click "OK". Restart PC afterwards and you will be good to go. Now, you can preview the PDF file again with Outlook.

Way 8. Deleting Temporary Files

Temporary files are saved in Windows OS for better performance. Temp or cache files may cause issues with PDF handler. Delete temp files to resolve PDF preview handler Outlook issue.

Step 1: Open Outlook app then press "Win + R" and input this path "%localappdata%\Microsoft\Outlook" and press Enter. Delete all folders that end with the following extensions:

• Tmp
• Dat
• Obi
• Olk

Way 9. Solve the Registry Issues

Sticking to an older version of Adobe Reader might have caused the issue for you. If you do not want to update Adobe Reader, you can fix registry issues with these steps to solve the PDF Preview Handler issue:

Step 1: Type and run "regedit" after opening Run program by pressing "Win + R". Now go to "HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Classes\CLSID\{DC6EFB56-9CFA-464D-8880-44885D7DC193}" path in registry editor. Here you will double-click AppID option and replace value data by "{534A1E02-D58F-44f0-B58B-36CBED287C7C}" then click "OK", close it and restart your PC.

Way 10. Repair Corrupt File

If none of the solutions above fixed the issue for you then you may have a corrupted PDF file. You can see whether you can open that PDF in some other PDF reader like UPDF or not. If it does not work as well, then it is corrupted. Alternatively, you can try to open other PDF files in Outlook to see if you will have the same problem. If not, then, it may be the problem of your PDF Files. For this case, you can repair it by using tools like iLovePDF or trying other methods of repairing PDF files here. 

Open iLovePDF PDF repair tool and upload your PDF using "Select PDF File" button. Click "Repair PDF" and the tool will automatically repair and download your file. Now, you can try to open the PDF file to see if the problem is fixed.

Part 2. Bonus Tip: The Best Tool to Preview or Read PDF If Outlook PDF Preview Handler is Not Working

While the 10 solutions discussed above are effective in most cases, they may not resolve the problem for everyone. It can become more frustrating in such a situation , so instead of trying to make Outlook work, you can switch to UPDF for previewing and reading your PDFs. UPDF is free for reading and viewing PDFs.

However, if you plan to upgrade to the pro version, you will get lots of additional features like editing PDFs and annotating PDFs to take notes when reading. The UPDF AI is also available to help you summarize, translate, review, explain, and more with the content in your PDF document. PDF reading experience with UPDF is also unique since you get a slideshow and many other options that you can explore. Just download UPDF via the below button and read the PDF file without facing the Outlook PDF preview handler not working issue.

UPDF brings you a rich PDF reading experience with lots of different features for different users like the following:

• UPDF AI: Translate, write, summarize, rewrite, explain, etc., with ChatGPT integration within UPDF.
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Final Words

Outlook is an email client that comes as a part of the productivity suite from Microsoft. It is efficient at doing many things like managing emails, calendars, etc., and one of its features is previewing PDF documents. However, sometimes, this software fails to assist you with that feature and gives the PDF Preview Handler error straight away. If you also faced this situation then we hope that this guide has been helpful with 10 different ways to fix the problem.

However, if the fixes didn't work for you or you don't want to go through the complex process of trying multiple solutions then you must try UPDF. UPDF is a complete PDF suite with great PDF preview and reading capabilities.