Error zero

[Iservi]

I got a problem I don't understand.

I am developing a VB application for a customer. On my PC's the application
is running OK, but on the customer PC the app hangs. When I look at the err
log I only got the message that the error nr is 0. Normally this line
appears only in my err.log when I forgot "Exit Sub/Function" before the
error handler. But this is not the case here.

I had the problem myself at the beginning of the project when I tested the
app on my test PC (On my dev PC the problem did not occur; everything worked
well there). The line where the zero error ocurred, tried to access a table
in a MS Access (mdb) database file. Since the referenced DAO was updated to
version 4 (MS Access 2000) and the database was constructed using MS Access
97, I changed the reference back to DAO 3.51. After that the zero error
disappeared until now.

Since I can only guess I has something to with a bad reference to a DAO
library; I don't know what is causing the problem however. Completely
reinstalling the app on the customers PC does not help.

I got the following questions.
First of all; how can a "zero error" act a as normal (that is a non zero)
error, by jumping form a valid line of code to the err handler like a normal
error? (Also the Err.LastDllError returns a zero.)
Secondly, what is the cause, so I can tackle this problem.

I appreciate any help.

Hans Heezemans
[e-mail]
www.iservi.com

[hal boyles]

Does the other PC have the DAO 3.51 referenced file?

[hal boyles]

Step thru the code line by line and check all the pertinent values at the
point of failure.

[Iservi]

Yes it has.

Hans Heezemans
www.iservi.com

"hal boyles" <ha********@timeinc.com> schreef in bericht
news:bk**********@inntp-m1.news.aol.com...

Does the other PC have the DAO 3.51 referenced file?

[Iservi]

I have done that. Code that runs without any problem on my Developer PC now
gives will generate the zero error when accessing a table in the MDB file.
The table and the file are OK and the installation proces has been OK; all
files and DLL's are installed.

Hans Heezemans
www.iservi.com

"hal boyles" <ha********@timeinc.com> schreef in bericht
news:bk**********@inntp-m1.news.aol.com...

Step thru the code line by line and check all the pertinent values at the
point of failure.

[Pieter Linden]

Hans,

just wondering, but what happens if you try to compile the code on
the machine you're installing on? (Or is that not an option?) If you
go to Tools/References, do you get MISSING next to any of your
referenced libraries? that *might* be the cause of your problem.

[Iservi]

"Pieter Linden" <pi********@hotmail.com> schreef in bericht
news:bf**************************@posting.google.c om...

Hans,

just wondering, but what happens if you try to compile the code on
the machine you're installing on? (Or is that not an option?) If you
go to Tools/References, do you get MISSING next to any of your
referenced libraries? that *might* be the cause of your problem.

Thanks for Your reaction Pieter,

but compiling the code on the client machine is not really a option. Besides
that the problems he has are gone since I send him a copy of the latest
version of the database (he apparently forgot to update it). So in a way the
problems have to with missing elements in the database and also not; because
when the database is completely up to date, the zero error still occurs.

Hans Heezemans
www.iservi.com

[Iservi]

"hal boyles" <ha********@timeinc.com> schreef in bericht
news:bk**********@inntp-m1.news.aol.com...

Step thru the code line by line and check all the pertinent values at the
point of failure.

Thanks for the reaction Hal,

but I can do that only on a developers PC and there the complaint does not
occur. If I install VB on the client (or my test PC) that PC will become a
developers PC and (to my experience) usually will not have the problem any
more. So I am not inclined to try that. Which is not to say I will not try
it if the problem continues.

Hans Heezemans
www.iservi.com

[Iservi]

"hal boyles" <ha********@timeinc.com> schreef in bericht
news:bk**********@inntp-m1.news.aol.com...

Does the other PC have the DAO 3.51 referenced file?

Yes it has. DAO 3.51 is part of setup program. The only thing is that the
client also has Access 2000; which might interfere, but to my experience if
DAO 3.51 is installed last, no problems should occur. And by reïnstalling
anew (which we did) the program the references to DAO 3.51 are reset if they
were overwritten by Acces 2000. Furthermore the client has Windows XP, so
DAO 3.51 "should" work with my app despite the presence of Access 2000.

Hans Heezemans
www.iservi.com

[Hans Heezemans]

I want to thank all contributors. I can initiate the error zero on my
developer PC by a) making the reference to msjet35.dll invalid or b) by
making a table corrupt and subsequently run the compiled exe file. I know
now how to solve the problem.
Yours friendly,

Hans Heezemans
[e-mail]
www.iservi.com