Built-in Chrome PDF Viewer does not fully load large PDF file for authenticated users in ASP.NET Web App

Question

The Built-in Chrome PDF Viewer does not fully load large PDF files for authenticated users.

Steps to reproduce in my environment:

1. In Visual Studio 2019 create a new WebForms project with Individual User Accounts authentication
2. In solution explorer create some folder e.g. MyPDFs and put inside some large pdf file.

3. Secure this folder with web.config:

   <location path="MyPDFs"> <system.web> <authorization> <deny users="?" /> </authorization> </system.web> </location>

   and for this testing purposes set runAllManagedModulesForAllRequests to true:

   <modules runAllManagedModulesForAllRequests="true">

4. Run this site with IISExpress and navigate to ~/MyPDFs/A17_FlightPlan.pdf in my case it is https://localhost:44302/pdfs/A17_FlightPlan.pdf

5. The login screen appears, after user successful logins the pdf is partially rendered (only first page) by built-in Chrome PDF viewer (pdfium)

6. When you remove authorization rule from web.config, or you put the PDF file to some other location, it is loaded correctly

7. The same behavior I can reproduce on production - Full IIS

8. Other browsers work fine: FireFox, EDGE, or even Chrome with replaced built-in PDF viewer for Adobe Acrobat reader extension

Where could be the problem? Are the headers OK?

Answer 1

It was a bug in Google Chrome. In Chrome Version 81.0.4044.43 (Official Build) beta (64-bit) it seems working.