Help us debug Sumatra hangs or crashes
If Sumatra crashes or hangs reliably on your machine but we can’t reproduce it ourselves, you can help us by debugging it. Here’s a tutorial on how to do it.
Please first test with latest pre-release version from https://www.sumatrapdfreader.org/prerelease.html
Some bugs might already be fixed there compared to latest
Those instructions require SumatraPDF 3.2 or later.

Getting logs #

We log information that might be helpful in diagnosing issues.
To see the logs: Ctrl + K (Command Palette), type show log
This saves logs to a file and opens default editor for .txt files with log file.

Install necessary software #

First, vocabulary. %ProgramFiles% means the standard directory where Windows installs programs. It’s c:\Program Files on 32-bit Windows and c:\Program Files (x86) on 64-bit Windows.

Debugging a crash #

To debug crashes:

Debugging a hang #

Here are the steps to follow if Sumatra hangs
  1. Start SumatraPDF.exe and get it to hang
  2. start WinDBG.exe
  3. use File/Attach to process (F6) and select SumatraPDF.exe from the
  4. In WinDBG, type:
7.1) .sympath+ SRV*c:\symbols*https://msdl.microsoft.com/download/symbols
7.2) ~*kb
7.3) lmf
Attach the output to bug report.

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