Forums Bug Reports mIRC 7.27 and 7.29 causing BSODs under WinXP SP2

1. Run installer (mirc727.exe or mirc729.exe)

Installation options:
- Path: c:\mirc727 or c:\mirc729
- Installation type: Full
- [ ] Add Desktop Shortcut
- [ ] Add StartMenu Shortcuts
- [ ] Backup Current Files
- [ ] Automatically Check for Updates
- [x] Run as Portable Application

2. Start c:\mirc727\mirc.exe or c:\mirc729\mirc.exe

3. Click [Continue] on greeting dialogue

4. Close mIRC

5. Start c:\mirc727\mirc.exe or c:\mirc729\mirc.exe again, and entire OS immediately either freezes up (a la 100% CPU use) or BSODs with:

STOP: c000021a {Fatal System Error}
The Windows Subsystem system process terminated unexpectedly with a status of 0xc0000005 (0x7c911f6c 0x00ebef80).
The system has been shut down.

This is repeatable for me. The BSOD (or freeze) occurs every time mIRC is executed for the second time. The issue has never occurred on this system with previous versions of mIRC (i.e., I can start and re-start mIRC 7.25 an infinite number of times on this system without problems).

This is occurring on a Windows XP SP2 machine with no Microsoft updates applied (except KB893357) and no anti-virus or other security software. (Please, no lectures; the system is used for development testing.)

Needless to say, the issue does not occur on any of my other machines, including a fully updated XP SP3 machine.

Khaled, can you think of anything that changed after 7.25 which might be responsible for this?

Can anyone else who has XP SP2 test for the occurrence of this bug?

one question, where is it putting applications data (like scripts) my system has mirc.ini in root for all my versions of mirc so i so not use system area for any data.. if yours is like this, i will try to duplicate...

Thanks for offering to test this.

In answer to your question, mirc.ini and the scripts subdirectory are both in the same folder as mirc.exe. (I was installing mIRC as a portable application each time.)

thanks for info.. will try my best to get a portable copy installed some time today and test.

There were hundreds of changes between v7.25 and v7.27, so it would be difficult to know exactly what particular change may be the cause. That said, I usually only test mIRC on fully updated versions of Windows, as service packs fix a whole range of Windows bugs and issues. It would be difficult to cater for all of the potential issues, side-effects and subtle bugs that older versions of Windows have. I am not aware of any feature in mIRC that caters for such issues. My advice to users is that they should always update Windows as not doing so leaves them exposed to a whole raft of security issues. I currently only have Windows XP SP3 installed, so I am unable to test under anything older than that unfortunately.

not unlike Khaled, I can not do this, because we are not at anywhere near the same update level.

Sorry

I managed to find an old XP SP2 CD and installed it. It took some time but I tracked down the issue to a critical manifest file parsing issue in XP SP2. Unfortunately the solutions described in that article do not resolve the issue. As this only happens with an old version of Windows that no one should be using anymore, I am not sure spending any more time on it makes sense.

Then I have interesting news. I applied the WindowsXP-KB921337-x86-ENU.exe hotfix from that article (and nothing else) to my XP SP2 test machine, and the issue was solved. mIRC 7.29 can now be started on it an infinite number of times without problems.

So, I'm curious why your results differed. Did you not apply the KB921337 hotfix, and only re-compile mIRC without the problematic manifest properties described by that article?

Anyway, assuming KB921337 solves the issue for you as well, and assuming that KB921337 is itself distributed by Windows Update to XP SP2 users, this bug report can be discounted (with my apologies for the false alarm).

P.S. I agree with your statement in your first post: I myself would not expect a software author to code work-arounds for issues caused by every level or permutation of incomplete patching across multiple legacy versions of Windows. When I reported this BSOD issue, I simply failed to consider the possibility that the incomplete patching of XP SP2 may have been the cause. Instead, and because it is a common occurrence today, I assumed that you had possibly coded an XP XP3+ dependant function without realizing it. Under that assumption, and since you support Windows 2000 onward, a bug report seemed in order.

P.P.S. On the subject of legacy operating system compatibility in general, count me as someone who appreciates your continuing support of them. I love software with a broad compatibility base. If you intend to continue supporting 2000, you might look into using a VM for hosting a fully-patched-except-for-SP3 installation of WinXP SP2. The reason: there are still more users of XP SP2 than of 2000. Using a VM would also allow you to test mIRC under a fully-patched (SP4+UR1) Windows 2000 when necessary.

P.P.P.S. HorseC, thanks all the same for your interest in helping.

"P.P.P.S. HorseC, thanks all the same for your interest in helping."

This is the ONLY time i have ever been thanked for not being able to help

But then, reading your comments to K about back level support, I can see your a very good thinker.

Thanks for your comments.

Glad to hear that resolved your issue. The KB921337 hotfix worked fine for me, however I assumed that as you were using Windows XP SP2, you were not updating your version of XP with all subsequent patches, which would normally take it to SP3 :-)

It was a tricky issue to track down as I had to slowly integrate changes from 7.27 in 7.25 and recompile after each change to pin it down. I was pretty sure it was not a non-supported function issue as, usually, if an application uses a non-supported function, Windows will display an error dialog the moment you try to run that application.

I try to make sure mIRC uses functions that are available across all supported versions of Windows. If a function is only supported in a newer version of Windows and I need to use it to support a new Windows-specific feature, mIRC uses dynamic loading to ensure it continues to work on older versions of Windows.