FIX: "Unable to Create File Buffer" 32-Bit ODBC Error

ID: Q130719

The information in this article applies to:

The Microsoft Foundation Classes (MFC), included with:
- Microsoft Visual C++ for Windows, 16-bit edition, versions 1.5, 1.51, 1.52
- Microsoft Visual C++, 32-bit Editions, versions 2.0, 2.1, 2.2

SYMPTOMS

After a long period of successful operation, an application generates the following ODBC error when that application uses the MFC database classes such that the 32-bit ODBC cursor library:

General error: Unable to create file buffer
State:S1000,Native:0,Origin:[Microsoft][ODBC Cursor Library]

CAUSE

The ODBC cursor library generates temporary files for its own use. To ensure that the temporary file names are unique, the 32-bit ODBC cursor library generates temporary file names that include a hex number. That number is incremented every time a new filename is generated. Here is an example of filenames that are genrated by the cursor library for its temporary files:

CTT1111.TMP
CTT1112.TMP
CTT1113.TMP

When the hex number embedded in the filename wraps from FFFF to 0, the error is generated:

CTTFFFD.TMP
CTTFFFE.TMP
CTTFFFF.TMP
CTT0.TMP <-- This temporary filename causes the error

RESOLUTION

To avoid the error, create a file named CTT0.TMP, and place it in the directory that the cursor library uses to generate its temporary files. Temporary files are created in the current working directory with the 32-bit cursor library. The cursor library will see the existing file with that name and skip over it to the next filename (CTT1.TMP).

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This problem has been corrected in the ODBC cursor library that ships with Visual C++ 4.0 and 4.1 (ODBCCR32.DLL, version 2.50.3006).

MORE INFORMATION

This problem applies only to the 32-bit ODBC components. However, the 16-bit MFC programs can thunk to the 32-bit components when running on Windows NT if you've set up a 32-bit data source rather than a 16-bit data source.

The error described in this article can appear for other reasons. Please see the following article in the Microsoft Knowledge Base:

Q115516 PRB: S1000: "Unable to create file buffer" ODBC Error

In general, other reasons produce a failure immediately upon trying to use the ODBC components. The problem described in this article produces a failure after a long period of successful operation. For example, doing a large number of requeries can cause the error.

Additional query words: 2.50 2.51 2.52 2.52a 3.00 3.10 3.20

Keywords : kbDatabase kbMFC kbODBC kbVC
Version : 1.50 1.51 1.52 1.52a | 2.00 2.10
Platform : NT WINDOWS
Issue type :