I have had issues for several months with the thumbnails on PDF icons only. They are sometimes transparent, solid black, or have the PDF icon only. I have uninstalled and reinstalled many times. I have "enable PDF thumbnails in Windows Explorer" selected. Adobe Acrobat DC Reader is my default program with version 2021.001.20135. I have tried many things over a while, as this really was bugging me. Tonight I installed "Fixes for 64-bit Adobe Reader preview handler and thumbnails" from:
https://www.pretentiousname.com/adobe_pdf_x64_fix/index.html#thank

I figured I had nothing to lose and surprisingly it fixed the issue, especially as it hasn't been updated since 2011.

Please build into Adobe Acrobat DC Reader a means to reset Adobe's PDF preview handler and thumbnails on 64-bit versions of Windows. Uninstalling and reinstalling doesn't fix it. Believe me...I have tried.

I attach a simple PDF file allcaps.pdf . The file prints fine. But when rendered on screen, the text in all capitals is not properly rendered. At 400%, it is fine. See 100percent.jpg for the screenshot showing the funky rendering and 400percent.jpg showing that it is fine when zoomed in. The Chrome and Firefox PDF renderers have no issues with this file. This seems to relate to the resolution used in the setting Page Display -> Resolution. If I use system setting (96 pixels/inch) and then set the zoom to 96%, it is fine. If I use a custom setting of 100 pixels/inch and set the zoom to 100%, it is fine. But if there is a slight mismatch (system setting at 96, zoom at 100, you get the funky display)

Adobe Reader version 2021.001.20135, Windows 10.

This issue is best illustrated with an example.

I generated a 5x5 png test image (test1.png) with transparent background and a 1 pixel wide green strip through the middle, embedded it into an svg (test1.svg), converted it to a pdf using inkscape (test1.pdf) and then viewed it in Acrobat Reader DC on windows 10, downloaded and installed today (2020-01-27). The result is shown in the attached image test1_acrobat_windows.png.

Notice how the green band fades first to gray, then to white, instead of fading directly to white. The same pdf file rendered with PDF.js looks like one would expect, as seen in test1_out_pdfjs.png, which looks just like the svg file does.

The gray border goes away if the original png has a white background instead of a transparent background. The corresponding files for this case are test2.png (raw image), test2.svg, test2.pdf and test2_acrobat_windows.png.

This test case is of course a bit contrived, but this behavior has real-world consequences. For example, a pdf figure that includes a raster contour plot with lots of thin colored curves on transparent background, will appear desaturated, especially as one zooms out.

My guess is that the transparent pixels have a black (but invisible) color, and that the interpolation formula uncritically interpolates R, G, B and A between #00ff00ff and #00000000, resulting in intermediates like #00800080, which when alpha composited with white gives #80c080, a slightly green shade of gray. To avoid this happening, I think one would need to alpha-composite before interpolation instead of after.

Since I could only attach a single image to the post (even though it looked like I could upload multiple in the submission form), and the form crashed when I tried to upload a zip file containing them all, I have uploaded the zip file to the following address instead:
http://ur.amaurea.net/acrobat_bug_report.zip

We have a web based application running on our Citrix environment. We are running Windows Server 2016 (1607) and Citrix VAD 1912 LTSR CU1. The users login to the web based application and eventually it will trigger the opening of a PDF within Internet Explorer. This process will work most the time but we find after the user does anywhere from 7-10 instances of the process Internet Explorer will crash.

We first monitored performance on our server but identified there are no CPU/RAM bottlenecks. We even isolated users to one server to test and they still have the issue. We recently enable Crash Dumps for Internet Explorer so we can further determine the issue. I've reviewed the crash dump along with Microsoft and we've found the crash is due to AcroRd32.dll. We were running an older verison of Adobe Reader so I've updated to 2020.012.20041 and we have the same issue. Is there anyone on the Adobe side who can review the Crash Dump I have to provide insight as to what could be causing it? We've tried with Protected mode disabled and the issue continues.

Thank you!

Hi,

after provided more tests were found that (in my case) reason and solution (I saw that behaviour from August 2020 to till now)

Description of workaround and provided steps
- Openned pdf document in Adobe Acrobat Reader DC (still updated version, recently 2020.013.20074),
- In Adobe File/Share file/Outlook message (Office 365 still update, recently version 16.0.13530.20132, 64bit),
- Then is automatically opened Outlook new message,
- message is fulfilled with the data and addresses, then click on send,
- Outlook and Adobe are still opened,

• standard work in both and next application (time to time (hapened not always, olny sporadicaly), don´t know the trigger of issue, but Outlook is seems like freezen (no any reaction to command by mouse or keyboard) - then when you close (standard close of application, not kill the process) Adobe Acrobat Reader DC you can continue with work in Outlook, no further action are required).

Maybe you can find the code bug and reapair it (I will be happy if you can share your feedback).
Thank you.

Hello,

Problem description
Adobe Reader DC - crash during save pdf file after created signature

Used SW
- Win 10 (ver 10.0.19042.685)
- Adobe Acrobar Reader DC 2020.013.20074

in Adobe Acrobar Reader DC is document digitally signed and during saving the pdf file is Adobe Reader crashed (it is happened from last update of DC).
Attached dump reports for further analysis (link valid till 7th January 2021, xou can download dump files from link https://osram-my.sharepoint.com/:f:/p/m_salka/EvkOvT59codChrmsyZA-VdoBurOAkScYaTK02S-x38wIiw?e=CIDs9x).

If is needed to extend the validity of OneDrive link, please contact me.

Please give me feedback about result of your investigation and repair.
Thank you for make better Adobe Acrobat DC.