Solved Sitecore PDF Loading Issue

Are getting problem in viewing PDF files in your newly upgraded Sitecore environment? We came across the same bug while upgrading Sitecore to version 7.2 that in some browsers while opening PDF files, they get stuck. Surprisingly after that, pressing Ctrl+F5 was allowing to view PDF file. See below screenshot when the downloading stuck:

Sitecore PDF viewing stuck randomly

Workaround from Sitecore

In Sitecore 7.2, they gave workaround to solve the issue by forcing download of PDFs by doing below setting:
        <mediaType name="PDF file" extensions="pdf">
But, this is not the solution for our problem. We can't say our clients to download and view the PDF, it should be viewed in browser itself. We applied many tricks, and finally we solved it.

So, what was the issue?

After reverse engineering MediaRequestHandler, we came to know that Sitecore is downloading PDF content partially in range using HTTP 206 Status Code, which might be creating problems in different browser. In Sitecore versions earlier than before 6.5, Sitecore was downloading PDF or any other media in one go, which never failed.

So, one thing was sure that this bug was just because of Range Retrieval mechanism provided by Sitecore or the plug-in our browser does not support it. See below screenshot which shows how Sitecore downloads PDF content in range.

 Sitecore downloads PDF content partially in range

Final Solution

We just tried disabling the Range Retrieval Mechanism as below and found the bug resolved.
    <setting name="Media.EnableRangeRetrievalRequest" value="false" />
Many thanks to our colleague Sandeep Gupta who helped in the investigation.

Enjoy accurate media download now!!

Other Sitecore 7.2 Bugs Solved!


  1. This helped me to fix the issues faster! Thanks a lot


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