FIX: This PDF document may not display correctly

• This PDF document may not display correctly, it is a warning displayed in Firefox when trying to view PDF documents.
• It is caused by the built-in PDF preview that Firefox has and can be easily fixed.
• If you’d like to learn more about the PDF document format, scroll through our dedicated PDF section.
• You never know when you need a troubleshooting guide for your apps and devices, so check our Troubleshooting Center for easy access.

When trying to open a PDF in a web browser, mainly in Firefox, some users reported receiving the warning. This PDF document may not display correctly in all the documents you were trying to view.

Without downloading the document, your option was to open the document with a different viewer, as suggested.

The problem is caused by Firefox’s built-in PDF viewer that needs to be modified.

How do I correctly view PDF documents in Firefox?

1. Open a new Firefox window and type about: config in the address bar.
2. A window will open with a warning> accept the warning and open the settings window.
3. Type js in the search bar at the top.
4. Look for pdfjs.disabled with a value of true .
5. Change the value to  false using the lever on the right side.
6. Then open Firefox menu> Options.
7. Go to the Applications tab> find Portable Document Format (PDF) or Adobe Acrobat Document (PDF).
8. Click the drop-down menu on the right> Use other …> select Adobe Reader as the application to preview it in Firefox.

This will disable Firefox’s built-in PDF viewer and enable the Adobe Reader plug-in to view PDF files.

Note: If you want to save a Firefox web page as a PDF, follow these recommendations.

We hope this article has been useful to you. You can send us your suggestions using the comment sections below.

FAQ: Read more about PDF documents

• How do I create a PDF document?

In any Windows browser, you can use the default print option on the page you’re reading, CTRL + P, and choose to print to a PDF file instead of sending the page to a printer.

• Is Adobe Acrobat the same document as PDF?

No, PDF (Portable Document Format) is actually a type of document created by Adobe Acrobat.

• Is PDF better than Word?

It depends on the use of a specific document. Word may prefer to edit documents, but the PDF format is accepted as the official and most professional format.

Also, any other type of document can be converted to PDF for easier reading preview.