Program crash - no rhyme or reason

[John Grogan]

I am experiencing problems with one Visual Basic project. It is prone
to crashing - in the VB IDE and also when running a fully compiled
executable. When it crashes in the IDE, then VB terminates too with no
error message. When the standalone EXE crashes there are no error
messages either. The project is reasonably big - 60 forms, 20
modules, 7 class modules, and it references a couple of custom DLLs
too.

I've tried running Dr Watson and it reports nothing. Similarly the
Event Viewer has no errors either. When running in Debug mode, the
crash terminates VB. The crashes are unpredictable - don't always
happen at the same point.

Any suggestions? I'm running VB 6.0 Service Pack 5 on Windows XP
Professional.

[J French]

On 20 Apr 2004 02:27:48 -0700, jo*********@hotmail.com (John Grogan)
wrote:

I am experiencing problems with one Visual Basic project. It is prone
to crashing - in the VB IDE and also when running a fully compiled
executable. When it crashes in the IDE, then VB terminates too with no
error message. When the standalone EXE crashes there are no error
messages either. The project is reasonably big - 60 forms, 20
modules, 7 class modules, and it references a couple of custom DLLs
too.

I've tried running Dr Watson and it reports nothing. Similarly the
Event Viewer has no errors either. When running in Debug mode, the
crash terminates VB. The crashes are unpredictable - don't always
happen at the same point.

Any suggestions? I'm running VB 6.0 Service Pack 5 on Windows XP
Professional.

When did the problem start ?

[Randy Birch]

March 25th. <g>
(Don't ask the question if you don't want to hear the answer) :-)

--

Randy
"J French" <er*****@nowhere.com> wrote in message
news:40***************@news.btclick.com...
: When did the problem start ?

[J French]

On Wed, 21 Apr 2004 03:58:43 GMT, "Randy Birch"
<rg************@mvps.org> wrote:

March 25th. <g>
(Don't ask the question if you don't want to hear the answer) :-)

Heh,

I bet he did something to his system

Ah well, start stropping Occam's razor

[John Grogan]

er*****@nowhere.com (J French) wrote in message news:<40***************@news.btclick.com>...

On Wed, 21 Apr 2004 03:58:43 GMT, "Randy Birch"
<rg************@mvps.org> wrote:

March 25th. <g>
(Don't ask the question if you don't want to hear the answer) :-)

Heh,

I bet he did something to his system

Ah well, start stropping Occam's razor

?

After scouring the archives here I've set the project to compile to
"P-code" and it is slightly more stable, but still crashes
occasionally. Think it started to happen after I added custom DLLs.

[J French]

On 22 Apr 2004 04:51:04 -0700, jo*********@hotmail.com (John Grogan)
wrote:

<snip>

I bet he did something to his system

Ah well, start stropping Occam's razor
?

That means cutting out bits of the code until you isolate the problem.

After scouring the archives here I've set the project to compile to
"P-code" and it is slightly more stable, but still crashes
occasionally. Think it started to happen after I added custom DLLs.

'Real' DLLs or AX things ?

If it is 'real' DLLs then you might have faulty declarations, or the
DLLs themselves might be buggy.

[John Grogan]

er*****@nowhere.com (J French) wrote in message news:<40****************@news.btclick.com>...

On 22 Apr 2004 04:51:04 -0700, jo*********@hotmail.com (John Grogan)
wrote:

<snip>

I bet he did something to his system

Ah well, start stropping Occam's razor
?

That means cutting out bits of the code until you isolate the problem.

Thanks - it was actually the March 25th reference that I didn't
understand though ;)

After scouring the archives here I've set the project to compile to
"P-code" and it is slightly more stable, but still crashes
occasionally. Think it started to happen after I added custom DLLs.

'Real' DLLs or AX things ?

If it is 'real' DLLs then you might have faulty declarations, or the
DLLs themselves might be buggy.

ActiveX DLLs - I picked up some sample code that creates a wrapper
round a third-party Mapping ActiveX that's a major part of my project.
The sample project that I downloaded works fine, but the wrapper DLL
seems to be causing problems in my own project.

[Randy Birch]

: Thanks - it was actually the March 25th reference that I didn't
: understand though ;)
JG: I am experiencing problems with one Visual Basic project....

JF: When did the problem start ?

RB: March 25th. <g>

Nothing more than a (humorous) example of answering the question asked.
Y'know, the type of answer a systems op could expect to get from an
end-user.

--

Randy

[J French]

On 23 Apr 2004 07:58:22 -0700, jo*********@hotmail.com (John Grogan)
wrote:

er*****@nowhere.com (J French) wrote in message news:<40****************@news.btclick.com>...

On 22 Apr 2004 04:51:04 -0700, jo*********@hotmail.com (John Grogan)
wrote:

<snip>

>> I bet he did something to his system
>>
>> Ah well, start stropping Occam's razor
>
>?

That means cutting out bits of the code until you isolate the problem.

Thanks - it was actually the March 25th reference that I didn't
understand though ;)

That was Randy - not me

>
>After scouring the archives here I've set the project to compile to
>"P-code" and it is slightly more stable, but still crashes
>occasionally. Think it started to happen after I added custom DLLs.

'Real' DLLs or AX things ?

If it is 'real' DLLs then you might have faulty declarations, or the
DLLs themselves might be buggy.

ActiveX DLLs - I picked up some sample code that creates a wrapper
round a third-party Mapping ActiveX that's a major part of my project.
The sample project that I downloaded works fine, but the wrapper DLL
seems to be causing problems in my own project.

Ok, for a start put : Option Explicit: DefObj A-Z
at the top of every Form, BAS module Class etc
- it may make something jump out of the woodwork

If that does not solve the problem (and it probably will not, but it
is good practise) then examine /all/ API Calls very carefully.
A faulty definition can give just such problems

Stick in Error Handling and see whether anything jumps out

I prefer On Error Resume Next, and to check everywhere for an Error,
but you would be wise to start off with On Error Goto

If none of these work, then backup your App (ideally on a floppy) and
start hacking out chunks
These problems can be very hard to isolate, you may have to 'emulate'
the core AX control to see whether that is what is causing the
problem.

..... also it would be wise to do some sort of check to ensure that you
do not have mismatched DLLs or OCXes
- I'm not sure what the best method of doing that is under XP

I expect that AX Control came with a little setup utility, it is
possible that it has poisoned your setup.