Question

I have an application that uses the MS Access 2003 front end to connect to both a MS SQL and a Sybase database. This application uses VBA (Visual Basic 6) and this cannot be changed. We are in the midst of a conversion from Windows XP (where the application runs fine) to Windows 7.

On Windows 7, attempts to connect to the Sybase databsae fail. The application uses a pass through query and when the failure occurs, I receive the following message:

An unexpected error occurred in Call_SP.
Error number: 48
Error description: Error in loading DLL
Error source: Secure open security

The particular line of code where this is throwing the error is:

For Each qryDef In dbLocal.QueryDefs

The items in this line of code are defined like this:

Dim dbLocal As Database
Dim qryDef As QueryDef

Set dbLocal = CurrentDb()

When originally launching the application, there was a missing reference for Microsoft DAO 3.6 Object Library. I copied the dao360.dll file to C:\Program Files (x86)\Common Files\Microsoft Shared\DAO, registered it using regsvr32.exe, and set the reference (Tools -> References) to this file.

At this point, I suspect the problem may have something to do with user rights on this machine, but I’m stuck on where to start. Users do have “read and execute” rights on the dao360.dll file.

We have a lot of legacy apps written in Access, so our systems use Access 2003, but Word, Excel, and Outlook 2010. We are moving to Windows 7 64-bit.

Answer 1

If I was in your shoes, I would try the following:

1. Remove and re-install Access

   And I would run a registry cleaner like CCleaner to remove broken library reference from the registry before re-installing Access and applying all updates.
   The fact that the dao360.dll was missing or improperly registered shows that there is at least one installation issue on that machine.
   Also, remove and re-install your ODBC drivers for the other databases.

2. Try on the same machine from a different user

   Create a new user on the machine, then log under that user and check if you still get the issue.

3. Try from a different machine

   Use the same database, make sure the DAO references are selected, and try code query again.
   If it still doesn’t work, then there is another issue somewhere, and it’s not related necessarly to DAO.

4. You mention using Sybase and SQL Server.

   Are the ODBC drivers functioning properly? Could there be some corruption there too on the machine?
   What if you create a new database and try a single pass-through query using the same connection string?

5. 32 and 64 bits mixup

   Are you sure all dependent software and database drivers are installed for 32bit?
   If you are trying to access an ODBC data source that uses a 64bit driver from a 32bit app, it will fail.
   In Win7 x64 the ODBC console available from the Administrative Tools in the Control Panel is not 32bit!
   You need to create your DSN using C:\Windows\SysWOW64\odbcad32.exe instead.