Error: Unable to create or open the default database

Error Message

When opening ArcMap, the following error message is received on start-up:

Unable to create or open the default database. This error is due to one of the following conditions:

Insufficient disk space
Insufficient or incorrect access to: 
Invalid or corrupt installation of MSXML.

For additional information on this error and possible resolution please see Knowledge Base article KB38523
Screenshot of the error


In ArcGIS 10, one of the start-up processes is the creation and/or validation of a default file geodatabase in the <User Profile>\MyDocuments\ArcGIS folder of the user executing the software. The default geodatabase is used in many tasks throughout the application, and is required to effectively run the software.

As a result of one of the conditions described in the error message, the default geodatabase cannot be successfully created and/or validated, and the start-up of the application fails.

Solution or Workaround

To circumvent this issue, follow the steps below:

  1. Ensure that access to the default geodatabase, especially if it is stored in a network drive, is not prohibited by software such as firewalls or virtual private network (VPN) configurations. Esri recommends the default geodatabase be created in the local machine. To change the directory path to the new default geodatabase in the local machine, refer to How To: Set the default Home folder and geodatabase location for new map documents for more information.
  2. In Windows Explorer, right-click and open the properties of the drive for the new default geodatabase, such as the C:/ drive.
  3. Under General, ensure adequate free space is available on the drive. The default file geodatabase requires no more than .5 MB.
  4. In Windows Explorer, browse to the path for the new default geodatabase.
If the folder contains multiple versions of the Default.gdb, skip ahead to Step 6. Multiple default geodatabases have unique names, and they follow this naming convention: Default.gdb, Default1.gdb, Default2.gdb, etc. In Windows Explorer, file geodatabases display as folders with the name of the geodatabase followed by a .gdb extension.
  1. Right-click the folder, and open its properties.
  2. Under Security, ensure the user attempting to execute the software has Read and Write permissions.
  3. If one or more Default.gdb folders exist in the workspace described in Step 4, delete them.
  4. Rename the Default.gdb file. For example: 'Default_old.gdb'. A new Default.gdb file is created when ArcMap loads.
  5. Install MSXML 4.0 Service Pack 3 (Microsoft XML Core Services) .
  6. Restart the machine, and launch ArcMap. The application starts successfully.

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