Did you find a bug in Sumatra? Please create a bug report in our issue tracker.
Does it involve a specific PDF (or CHM or XPS or ...) 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 you're using the latest release version, please try the latest pre-release build. It's possible that bug has already been fixed.
If the file (or other information) is confidential, you can e-mail it directly to [email protected] (Krzysztof Kowalczyk, Sumatra's main developer).
If you report a crash, please:

suggest change to this page