Problem: Error reading textfile data. This could be due to corrupt ODBC/MDAC components


When opening ArcCatalog or browsing a directory which includes text files, the following error message may occur:

"Error reading textfile data. This could be due to corrupt ODBC/MDAC components. You may not have access to all the MDAC utilities you require. Please refer to the FAQ for further information".

This may also cause ArcCatalog or ArcMap to crash with an application error.


This could indicate that some of the Microsoft Data Access Components (MDAC) have become un-registered (this can occur after running the regclean utility) or corrupted on the local system. Other symptoms may include not being able to call up the Data Link Properties dialog when Add OLE DB Connection is selected.

Solution or Workaround

The instructions below include making changes to essential parts of your operating system. It is recommended that you backup your operating system and files, including the registry, before proceeding. Consult with a qualified computer systems professional, if necessary.

Esri cannot guarantee results from incorrect modifications while following these instructions; therefore, use caution and proceed at your own risk.
  • Re-register the msadce.dll file. This is usually located in C:\Program Files\Common Files\System\MSADC.
  • If that does not solve the problem on a Windows NT platform, re-install the MDAC (2.5) pack. This (and other MDAC packs) can be downloaded from http://www.microsoft.com/data/default.htm.
  • If re-registering msadce.dll did not solve the problem on a Windows 2000 machine, installing Windows 2000 SP1 and upgrading MDAC to version 2.6 may be required.(As MDAC are installed as system components under Windows 2000 they can not be un-installed without replacing operating system files that were upgraded by the MDAC installer.) Please consult the release manifest and specification for MDAC 2.6 before proceeding. There may be some issues with the latest version of MDAC that you should be aware of.

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