Did you encounter a bug in SumatraPDF?

Check in latest pre-release build

First, see if it still happens in latest pre-release version. It’s possible that a bug has already been fixed there.

Create an issue

If the problem is present in latest pre-release build, please create a bug report in our issue tracker.

Provide a test file

Does it involve a specific PDF (or CHM or XPS) file?
Please attach it to the issue (try dragging and dropping on the issue field). Without a test document we rarely can make progress on fixing the issue.
If the file (or other information) is confidential, you can e-mail it directly to kkowalczyk@gmail.com (Krzysztof Kowalczyk, SumatraPDF’s main developer).

Provide reproduction steps

Often the bug only happens in a specific scenario.
If possible, please provide step-by-step instructions for reproducing the the issue.

Reporting crashes

Submit crash report