Sumatra PDF is a PDF, ePub, MOBI, CHM, XPS, DjVu, CBZ, CBR reader for Windows

Can not install / update 3.2 (gives an error message)

Hello! I’m trying to run SumatraPDF-3.2-64-install.exe to update from 3.1.2 64-bit
(By the way: Should I uninstall the old version before installing the new one?)

The installer does not start, it show me an error that is something like that (I need to translate into English):
“The application has failed to start because its side-by-side configuration is incorrect.”

The old one, version 3.1.2, is still installed and working with no error shown.

Backup to a separate location any customisation,
e.g. as a minimum save a copy of your settings advanced options file (SumatraPDF-settings.txt).

Before I tell you to uninstall I need to know where your files came from as I never saw SumatraPDF complain of side-by-side, that sounds like one or other may not be from this master source?

Thank you for your answer
I’ve download it from this site ( ) on March 26th.

Even more oddly, I’ve download it again, and the newly downloaded installation works fine

They have the same size (9.161 KB) but they are different (I’ve used a file compare program and it has said to me “Binary files: file1 and file 2 are different”

Maybe the first went bed while I was downloading it? (But such a thin I’ve never happened to me).

Thanks for the feedback
Sometimes a glitch on the line, can cause a small mutation, but that message whilst valid for some broken applications certainly is not normal for Official SumatraPDF.

In the past there have been requests for MD5 or SHA1 testing which can give users some sense of security. However, my opinion is that no hash is better than a compromised one. Thus, I personally consider the best test is one based on herd immunity and often submit suspect files for analysis. One such good utility is which allows you to run your SHA-256 result through VirusTotal (however for recent files that have low exposure, results need to be treated with caution).

The downside is occasionally a false positive can be caused by bad analysis

I tried to update v3.1.2 to v3.2 (x64) but the installer crashes with an error (incorrect side by side configuration). Windows event logs do not give enough info to spot the problem. I retried v3.1.2 installer and also the v3.3.12538 pre-release instalers (both x64) and they worked Ok.

Also, installer for v3.1.2 x32 worked as well.



Second time of a similar report look at the md5 hash as shown above starts 632416f or check the download direct on virus total and if your file is not Signature Date 2020-03-15 00:42:## then it possibly did not complete well

I just downloaded twice to check both x64 installer links are the same as the original installer and virustotal reports sha 256 as

This problem seems to crop up for short periods see Dec 2017 Download for x64 installer broken
Unsure it it could be periods of high demand or perhaps a bunch of over zealous antivirus checkers b0rking the downloads

This happens to me every single time I try to download the latest 64-bit installable .exe

“Major operating systems will show end users an error message if the software they are trying to install is not signed”

The latest pre-release versions are currently unsigned (in part due to cash flow)

This thread is about 3.2 which was signed but fails to download correctly

Please clarify your use of the word “latest” is it Daily / Pre-Release (unsigned which will install with an error message) OR Full release signed

Please include some screenshot or wording to identify which of the many ways Windows creates its errors.
best test is to confirm that the date of signing is as shown above

There is a separate thread about downloads after 3.2 e.g. 3.2+