Freeze/slowness displaying a PDF in WebBrowser control (via MFC or WinForms)

Report · Oct 10, 2018

Hello, I'm having problems (freeze/slowness) by displaying a pdf in Ms IE WebBrowser control using the Acrobat Reader version 2018.009.20050; for instance, the page down/up is very slow.

The problem happens in an MFC application as well in C# WinForms when one of the parent windows of the web browser control has the Ms Windows extended style WS_EX_COMPOSITED (I've working samples if needed - both MFC and WinForms, sources and/or binaries).

When this style exists, I can observe that the AcroRd32.exe process has high CPU (~70%) and through Ms Spy++ I can see that Ms Windows paint-related messages don't stop to be generated, for instance, to the reader top toolbar; in this toolbar, it is also observed an unexpected horizontal line in the middle and at all length of the toolbar, and sometimes it generates flickering which matches the "repaint" that is being consecutively made.

In my application (MFC), and not in the samples that I've made to reproduce the issue, I had to tweak it by using the Ms Windows styles WS_CLIPCHILDREN and WS_CLIPSIBLINGS in one of the WebBrowser control parent windows, because it was freezing completely my application.

I've no idea if with older versions of the PDF reader this problem happened, or from which version the problem should start to happen, but only in the last year I've started to receive complains from my customers.

Is this problem known and there is a fix to it?

Report · Oct 10, 2018

Hello Antoniocunha,

We're sorry for the trouble you had, please install the latest update of Adobe Reader 19.008.20074 from help>check for updates, or manually from 19.008.20074 Optional update, October 08, 2018 — Release Notes for Acrobat DC Products

Reboot the machine if possible, and check.

You may also try the suggestions from the following help article Troubleshoot viewing PDF files on the web

Let us know how it goes and share your findings.

Thanks,

Anand Sri.

Report · Oct 15, 2018

Hello AnandSri,

I've uninstalled my Acrobat Reader version, installed 19.008.20071, applied the optional upgrade to 19.008.20074 and rebooted the machine.

The problem continues as initially reported.

Is it supposed to not happen in the new version? or was just to test if it continues to happen?

I don't know if it could be related, but if I go the IE Manage Add-Ons dialog, the Adobe PDF Reader reports the 19.8.20071 and not the 19.8.20074 version (see below). Is this expected?

Let me know what I can do more to help with this analysis. A sample application is very easy to do, but I can provide mine if you wish; btw, the PDF that I'm testing with is this one: http://www.pdf995.com/samples/pdf.pdf

From IE:

Name: Adobe PDF Reader

Publisher: Adobe Systems, Incorporated

Type: ActiveX Control

Architecture: 32-bit and 64-bit

Version: 19.8.20071.303822

File date: ‎20‎ de ‎setembro‎ de ‎2018, ‏‎07:32

Date last accessed: ‎30‎ de ‎agosto‎ de ‎2018, ‏‎12:01

Class ID: {CA8A9780-280D-11CF-A24D-444553540000}

Use count: 14

Block count: 0

File: AcroPDF64.dll

Folder: C:\Program Files (x86)\Common Files\Adobe\Acrobat\ActiveX

Regards,

Antonio Cunha