VB6 - runtime error 48 with C/C++ dll

Question

First of all I want to say that I read most of the other questions here with similar issues before posting this question. But my situation is slightly different.

I have an old VB6 application which uses a custom C/C++ dll to send/read data over TCP.

The app is on a shared network drive of a win2003 server which multiple users can access. The dll sits in the application path and I use declare to load it.

VB6:

Public Declare Function Interface_Open Lib "Interface.dll" Alias "Open" As Integer

C/C++ dll:

_declspec(dllexport) int _stdcall Open() { }

Now for the strange part: The application runs smoothly for 90% of the time. But some users experience random the runtime error 48 "dll not found" while others dont.

It seems to fail when I try to call the dll:

Interface_Open

Im not able to replicate the error on my win7 64bit machine thats what confuses me. I also checked the network permissions for the users on the share but they were fine.

I don't think the problem lies inside the C/C++ code because logs tell me it failes before entering the dll.

Should I return a long value instead of an integer? Could this be a reason why it fails to load the dll?

Answer 1

Integers are 16 bit in VB, for compatability with 16 bit VB. So an integer in any other language is called a long in VB.