Thunderbird doesn't open SumatraPDF in Edit mode


Hi guys! Problem with Thunderbird 52.5.2 on Windows 10, build 1709. Here’s what happens:

  1. Attaching a PDF while composing a mail, I save the mail as a draft.
  2. In the Drafts folder, when selecting that mail, I can open the PDF fine with Sumatra:
  3. When choosing Edit…, though, I cannot open the PDF any more. Double-clicking or selecting Open… simply does nothing: (sorry can’t attach another screen shot here because I’m a new user)
    This happens even with Thunderbird running in -safe-mode, so it’s not due to some extension/add-on.
    The weirdest thing is this happens only on my wife’s new Lenovo laptop, not on my own laptop, although we have the same Windows 10 build, the same TBird version, the same SumatraPDFreader version, the same PDF default settings.
    Any clues how to further debug this are appreciated. Thanks in advance!


Doesn’t seem to be Sumatra’s fault, but why don’t you run a quick test to check? With TB closed completely on both systems (not even running in the background, minimized to the tray etc.), on your wife’s laptop back up her TB profile folder to some other location and delete it. Copy over your profile folder’s contents using the instructions here, then launch TB. Now TB on your wife’s laptop should display your mail account and ideally behave the exact same way as on your laptop. Can you open PDFs in Edit mode now on her laptop?

If yes, that means it’s a problem with your wife’s TB profile. If no (i.e. your profile on her laptop still exhibits the same issue), it means the problem lies elsewhere. If Sumatra’s settings are also exactly the same on both systems, then perhaps there’s some difference in the registry settings related to PDFs.


Thanks Peter. Sure I could try and start Thunderbird on my wife’s laptop with my TBird profile. But assuming it behaved like on my computer, that would still leave me wondering what secret setting it is that makes TBird behave properly. (And anyway I’m fairly sure it just worked out of the box on my computer.) As I said, I had started TBird in safe mode on my wife’s computer, which disables any add-ons and generally starts with a fresh profile.
So next thing I’ll do is compare TBird settings to see if there’s anything subtle that differs. I also had a look at the Windows registry but that’s kind of hopeless. If I can’t fix it it’s not a disaster, but it nags me not to be able to track it down. :slight_smile:
Again, thanks for your help. If I find the solution to the riddle, I’ll post it here.