Results 1 to 5 of 5

Thread: _com_error at memory location 0x0dfcfc78

  1. #1

    _com_error at memory location 0x0dfcfc78

    I think there's a long standing bug in LW that's been around at least since LW9.3.1

    I was debugging a plugin of mine using Visual C++ 2008 and noticed when I used the filreq dialog there was a First-chance exception. Well, that can't be good I thought. So I spent an evening trying to spot the problem. Unfortunately I couldn't see anything different from the objseq example in the SDK samples. Since the exception didn't seem to cause any noticeable problems in my program, I almost decided to let it go. But then I thought, why not compile and debug the objseq example plugin. So after compiling I started the debug session with LW9.3.1

    Here's what makes me think the problem is actually in LW.
    The first thing I had to do was bring up the ADD PLUGIN under the Utility Tab in order to even have objseq available to debug. Well that brings up a dialog to select a plugin to add and guess what?

    Yes, you guessed it ... the exception occurs with using the Add Plugin File Dialog.

    So I tried it with LW9.5 -- same thing.
    And also same thing with LW9.6

    Perhaps this is just some weirdness I can forget about - but the Open scene dialog doesn't cause the problem - so that's seems to be clean code - or using some different methodology to select a scene.

    I think there may be some hidden errant code in LW that may even be causing other bugs that are more difficult to track down.

    I'll fog this Bug, but I thought I'd post this info in case some code guru might be able to explain this weirdness.

    Attached are some Visual C++ screen captures using LW 9.3.1 & LW9.5 & LW9.6
    Last edited by GregMalick; 02-24-2009 at 05:23 PM.

    Somewhere, over the rainbow....

  2. #2
    I just test at work under XP and it seems I only have this First-Time exception under Vista.

    Stranger & Stranger.

    Somewhere, over the rainbow....

  3. #3

    More Information

    The problem occurs for any default File Dialog (both Open and Save as). But the problem will not occur using the VBFileRequester.
    The problem only seems to occur under Vista, XP is OK.
    The problem only occurs the very first time you bring up the default File Dialog. Subsequent uses of the default File Dialog won't cause the First-Time Exception.

    I've have verified the problem using the
    Load Scene File Dialog
    Load Image File Dialog
    Load Windows Config File Dialog
    Load Item from sscene File Dialog
    Load Object File Dialog
    Save Scene As File Dialog

    My intuition & debugging skills tell me that something has changed in the Vista System File Dialog that LW is not taking into account. There are new options to search and change the directory in Vista's File Dialog which may have some bearing on the problem.

    Of significance is that the problem ONLY occurs the first time the File Dialog is used after starting LightWave. You can repeat the problem with the other File Dialogs by closing and reopening LW.

    And the problem is only visible if you are debugging using the Visual C++ 2008 Express Edition. LW seems to chug along it's merry way, but exceptions typically cause eventual grief and should be tracked down and eliminated. Problems can show up in very unrelated areas of a program and be very hard to duplicate.

    I'll post more info if I encounter it.

    Somewhere, over the rainbow....

  4. #4
    LightWave Engineer Jarno's Avatar
    Join Date
    Aug 2003
    Location
    New Zealand
    Posts
    597
    It may not be a LW problem at all. Windows does a bunch of stuff when opening a file dialog, including activating 3rd party file handlers through the COM interface. If one of those throws an exception, it can show up in the debugger like that.

    ---JvdL---

  5. #5
    Quote Originally Posted by Jarno View Post
    It may not be a LW problem at all. Windows does a bunch of stuff when opening a file dialog, including activating 3rd party file handlers through the COM interface. If one of those throws an exception, it can show up in the debugger like that.

    ---JvdL---
    That's a relief.
    Just trying to help out, here.

    I already zipped up the entire objseq SDK directory with all the MS-VS 2008 stuff and sent it to Jamie Finch in response to bugCase 19800.
    If someone at NT has Vista32 & Visual Studio C++ 2008 Express, they could try running it in debug mode and see if opening a file Dialog causes the problem.

    If not, it's probably on my side.
    And it's likely near impossible to figure out which 3rd party file handler is causing the problem. I'm not even sure what programs have instantiated themselves into file handling during their setup/installation.

    Yuck.

    Somewhere, over the rainbow....

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •